Geely JL481Q Manual Download Page 73

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he function of piston & connecting rod mechanism is to convert pressure of working substance in the cylinder into power

by rotation of the crankshaft and flywheel assy. Piston & connecting rod mechanism mainly consists of piston, piston rings,

piston pin, connecting rod body, connecting rod cap, connecting rod bolts, nuts and connecting rod bushing. The disas-

sembled piston & connecting rod mechanism of engine is illustrated in Fig. 173. The consolidation degree and power per

unit piston area of engine are high. The structures of canopy piston top, minus offset and semi-floating piston pin allow less

motor noise and more working flexibility.

Chapter 4 Piston & Connecting Rod Mechanism

Because short piston and low compression height helps to lighten piston weight and reduce reciprocating inertial force,

both of the compact engines can run at a higher speed.

Two gas rings and one oil ring is fitted on the piston head. The height of the first gas ring is 3mm and that of the secondary

one is 2.5mm. Eight oil feed-back holes of 2mm in diameter distribute symmetrically at the both sides of the pin hole on the

bottom of oil ring slot, and a piston pin lubricant track is designed on piston pin seat, which permits the continuous suction

of lubricant. To achieve fine thermal conductivity, heating surface on the piston top introduces the structure of smooth

transition, and a big transition circular is adopted to connect top plate and ring belt.

1. Structural Characteristics of Piston, Piston Pins and Piston Rings

1. Piston

The main functions of piston are to undergo high temperature and high pressure of working substance in cylinder, keep

airtightness of cylinder together with piston rings, and transfer heat to cylinder walls. The piston used in the engine is made

of cocrystallization aluminum-silicon alloy. Integral and tin-coated, it reduces the possibility of napping. Combustion cham-

ber, formed by piston top and cylinder cap, provides a large room for extruded gas. The projection of combustion chamber

offers a good shape for organizing whirl currents of extruded gas, and advances the features of high thermal efficiency,

small chill area and low knocking. The structure of piston is shown as Fig. 174.

Section 1 Construction of Piston & Connecting Rod Mechanism

1.First gas ring 2.Secondary gas ring 3.Combination oil ring 4.Piston pin 5.Piston

6.Connecting rod 7.Connecting rod bushing 8.Connecting rod cap 9.Connecting rod nut

Fig 173 Disassembled piston & connecting rod mechanism

Fig. 174 Structure of piston

Summary of Contents for JL481Q

Page 1: ......

Page 2: ...r Head Assembly 45 Section 1 Structural Characteristic of Cylinder Head 45 Section 2 Detach Assembly and Repair of Cylinder Head 45 Chapter 4 Piston Connecting Rod Mechanism 69 Section 1 Construction of Piston Connecting Rod Mechanism 69 Section 2 Dismantling and Inspection of the Connecting rod and its Bearing 72 Section 3 Common Faults and Troubleshooting of the Piston Connecting rod Mechanism 7...

Page 3: ...Evaporative Emission Positive Crankcase Ventilation Control System 124 Chapter 8 Ignition System 127 Section 1 Introduction to Ignition System 127 Section 2 Troubleshooting of Ignition System 128 Chapter 9 Lubrication System 132 Section 1 Makeup and Features of Lubrication System 132 Section 2 Examination Maintenance of Lubrication System 136 Section 3 Common Faults and Troubleshooting of Lubricat...

Page 4: ...erating Mechanism 173 Section 2 Battery 175 Section 3 Normal Malfunction of Charging System and Troubleshooting 176 Chapter 14 Starter 177 Section 1 Structure of Starter 177 Section 2 Working Principle of Starter 178 Section 3 Attentions in Use of Starter 178 Section 4 Troubleshooting of Starter 179 Chapter 15 Engine Management System 180 Section 1 System Profile 180 Section 2 System Composition a...

Page 5: ...tra heat or mechanical load 2 Crankshaft Connecting Rod Mechanism The crankshaft connecting rod mechanism is composed of body piston connecting rod crankshaft flywheel and crank shield It converts the heat generated by engine combustion into mechanical energy namely converts the piston linear reciprocating movement into the crankshaft and flywheel rotations and then the flywheel outputs the power ...

Page 6: ...ystem The startup system is composed of startup motor and its accessories It s designed to start up the engine from statistic mode to automatic operation 9 Engine Management System The engine management system is also called the engine control system It s composed of sensors that measure the engine operation status and parameters the Electronic Control Unit ECU and the controlled acting components...

Page 7: ...ll be keep at the best level Improving properly the engine compression ratio i e the ratio of maximal cylinder capacity vs post compression minimal capacity may make the engine more powerful and cost effective 3 Power Stroke The power stroke is the process in that the combustible gas mixture burns and expands to generate power in the cylinder At this moment the intake valve is still closed Before ...

Page 8: ...igh as 10 to 35kV for ignition With the overall displacement of and engine and engine are cylinder in line water cooling 4 stroke gasoline engines equipped with double over head camshaft 16 valve and electronic control fuel injection There re the oxygen sensor and the three way catalytic converter in the exhaust pipe ECU controls the switch of cooling fan in the engine according to the change of c...

Page 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...

Page 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...

Page 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...

Page 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...

Page 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...

Page 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...

Page 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...

Page 16: ... rate SG or above 90 294 539 3 5 full in dry mode 3 1 full in wetmode Force cycle water cooling 0 8 0 1 Type Bore stroke mm mm Displacement L Compression ratio Rotation at idle speed r min Ignition timing Valve clearance Intake mm In cold state Exhaust mm maximum power KW r min Maximal torque N m r min Minimal fuel consumption ratio at full load g kw h Emission at idle speed CO HC PPm Test cycle e...

Page 17: ...ce mm MR481QA JL481Q II Major Technical Parameters of MR481QA Engine and JL481Q Engine 4 cylinder in line water cooling dual roof convex shaft 16 valves belt and gear driven hip shaped combustion 81 77 81 85 5 1 587 1 762 9 6 9 6 800 50 Dynamic adjusted by ECD with the condition 0 20 0 05 0 30 0 05 78 7 6000 83 1 5600 137 4400 156 8 3400 269 269 0 1 50 NO 93 or above Lead free vehicle gasoline Pre...

Page 18: ... of fixed engine load the throttle opening angle is fixed The speed feature in the case of full engine load the throttle is completely opened is called the exterior feature The exterior feature curve describes the maximal power maximal torque minimal specific fuel consumption of engine and the corresponding changes of engine rotation speed as shown in Fig 10 Fig 11 Fig 12 and Fig 13 Fig 10 Exterio...

Page 19: ...15 ge g kwh n r min Power Me N m Torque Pe Kw Fuel Consumption Ratio Rotation Speed Fig 11 Exterior Feature of MR479QA Engine ...

Page 20: ...16 n r min ge g kwh Fuel Consumption Ratio Rotation Speed Power Me N m Torque Pe Kw Exterior Feature of MR481QA Engine Fig 12 ...

Page 21: ...17 Fig 13 Exterior Feature of JL481Q Engine Power Me N m Torque Pe Kw ge g kwh Fuel Consumption Ratio ...

Page 22: ...Standard Allowed limit Standard Allowed limit Standard Allowed limit Maximal correction Standard Allowed limit Intake Exhaust Standard Standard Seat surface width mm Valve race surface angle Intake bearing hole Exhaust bearing hole Standard Lower surface flatness mm Flatness of manifold interface mm Valve seat Allowed concave in valve seat surface mm Standard value of cam shaft bearing hole mm Sta...

Page 23: ...ce mm Name of item Servicing data Journal uneven abrasion mm Thrust bearing clearance mm Gear clearance mm Upper surface flatness mm Diameter of cylinder head bolt mm Cylinder hole roundness mm Cylinder hole perpendicularity mm Cylinder hole dimension for servicing mm Clearance between piston skirt and cylinder hole mm MR479Q and MR479QA JL481Q and MR481QA MR479Q and MR479QA JL481Q and MR481QA 1 t...

Page 24: ... 480 2 350 0 015 0 100 1 486 1 490 1 490 1 494 1 494 1 498 1 606 1 610 1 610 1 614 1 614 1 618 Central wall thickness of connecting rod bearing shell mm Clutch interface run out mm Thickness of thrust plate mm Connecting rod journal diameter mm Master journal diameter mm Axle clearance mm Journal uneven abrasion mm cylindricity Clearance to ring groove edge mm Opening clearance mm 1 to 2 rings Oil...

Page 25: ... block Cylinder block Cylinder head Cylinder head No 2 water inlet Cylinder head Intake manifold Name Spark plug Cam bearing cover bolt Cylinder head hood bolt Ignition device Camshaft timing belt wheel Belt tension wheel Crankshaft tension wheel Cylinder head 1st screwing Cylinder head 2nd screwing Cylinder head 3rd screwing Generator stand No 2 water inlet Oil position ruler conduit Intake manif...

Page 26: ...nder head Exhaust manifold Cylinder block Exhaust manifold Cylinder block Cylinder block Cylinder block Connection rod body Cylinder block Cylinder block Cylinder block Cylinder block Cylinder block Cylinder block Crankshaft Cylinder block Exhaust manifold Cylinder block Cylinder head Regulator seat Name Fuel in pipe Cooling water bypass hose Intake manifold seat Intake manifold seat Engine stand ...

Page 27: ...lace the oil 4 Seasonal maintenance a Add anti freezer into coolant in the winter days b Adjust the concentration of storage battery electrolyte on seasonal basis 1 Maintenance Periods and Maintenance Content Section 5 Maintenance of Engine Specification of applicable oil SAE10W 30 or SAE10W 40 SAE15W 40 frigid zone SAE5W 30 API grade above SG 1 Check whether the engine oil is in bad quality mixed...

Page 28: ...s in cold state a Turn the crankshaft pulley to align the V groove on it to the timing mark O on the No 1 timing belt cover Check whether the mark K on the camshaft timing pulley is in line with the timing mark U on the bearing cover If not turn the crankshaft a circle 360 b Measure the clearance between the 1 2 cylinder intake cam and the 1 3cylinder exhaust cam and the valve tappet with the thic...

Page 29: ...k plug if it s not in normal condition The recommended spark plug is MR479Q MR479QA DENSO K16R U MR481QA JL481Q K7RF 11 2 Bend the outer side of electrode gently in order to obtain the necessary electrode clearance 0 8mm in normal case 3 Install the spark plug using a spark plug wrench with a torque of 18N m 7 Replacement of oil filter Replace it per 40 000km or 24 months in normal case 8 Check an...

Page 30: ...ht These engines are suitable to the transverse mounting front installed and front wheel driving 4 The cylinder block is compact The cylinder center distance is 87 5mm There s the main oil passage in the cylinder block connecting to the oil pump oil filter and oil pressure sensor directly There s optimized layout for cooling system of water cavity and water flow And the servicing is easy Fig 15 Ch...

Page 31: ... 2 MR479Q MR479QA MR481QA JL481Q MR479Q MR479QA 18mm from bottom to up MR481QA JL481Q 16mm from bottom to up Diameter of cylinder bore Piston skirt diameter Diameter of main bearing seat hole Diameter of crankshaft main journal Red Yellow Blue Red Yellow Blue Red Yellow Blue Red Yellow Blue Red Yellow Blue Red Yellow Blue 0 01 0 0 01 0 0 01 0 0 01 0 0 02 0 01 0 02 0 01 0 02 0 01 0 02 0 01 0 03 0 0...

Page 32: ...QA JL481Q Total central thickness of crankshaft bearing Diameter of connection rod big end Diameter of connecting rod shaft Central wall thickness of connecting rod bearing shell Red Yellow Blue Orange Green Red Yellow Blue Red Yellow Blue Red Yellow Blue Red Yellow Blue Red Yellow Blue 0 005 0 002 0 008 0 005 0 011 0 008 0 014 0 011 0 017 0 014 0 008 0 0 016 0 008 0 024 0 016 0 006 0 0 018 0 012 ...

Page 33: ... 13 Lift the car to proper height with the automobile lifting equipment Make sure the car to be locked and secured on lifting equipment 14 Drain the oil in the oil pan 15 Drain the gear oil in the gearbox 16 Detach off the front left propeller and the front right propeller 17 Remove the exhaust pipe and muffler assy 18 Remove the gear shift lever 19 Intrude the engine lifting equipment below the c...

Page 34: ... head cover and the gasket Fig 17 7 Remove the AC generator 8 Remove the exhaust manifold Fig 18 9 Remove the phase sensor 10 Remove the intake manifold 11 Remove the oil dipstick and the guide Fig 19 12 Remove the No 2 water inlet flange and the gasket Fig 20 13 Remove the No 3 and No 2 timing belt cover 14 Set the No 1 cylinder at TDC of compression stroke 1 Turn the crankshaft pulley gently to ...

Page 35: ... exterior side surface of timing belt Fig 22 15 Detach the crankshaft pulley Fig 23 16 Remove the No 1 timing belt cover and the timing belt and don t forget to make the match marks on the pulley and the belt 17 Remove the crankshaft timing pulley 18 Remove the camshaft timing pulley Fig 24 19 Detach the camshaft Note The axial clearance of camshaft is quite small so keep the camshaft horizontal d...

Page 36: ...If the No 1 bearing cap can t be removed by hand leave it where it is with no bolt and do not remove it by force Fig 30 b In the sequences shown in the figure screw off and remove the 8 bearing cap bolts by multiple and equal actions Fig 31 After removing the cam bearing cap if the camshaft can t be lifted up vertically reinstall it to the No 3 bearing cap with 2 bolts and loose and remove the 2 b...

Page 37: ... and put it on the worktable Be careful to protect the contact surface between cylinder head and cylinder block and pry inside the bulge between them with the screwdriver during the course of disassembly Fig 34 Fig 34 Proper Way of Prying apart the Cylinder Head from Cylinder Block Gently Fig 33 Sequences of Loosen off and Detaching the Cylinder Head Bolts Fig 32 Proper Way of Lifting up the Exhau...

Page 38: ...aped ring 6 Remove the oil filter 7 Remove the oil pressure switch 8 Remove the knock sensor 9 Remove the oil sump pan and the oil pump 10 Remove 6 bolts and remove the rear oil seal retainer and gasket Fig 39 III Disassembly Examination and Servicing of Cylinder Block Fig 35 Detach the Flywheel Fig 36 Detach the Rear end Cover plate of Cylinder Block Fig 37 Detach the Adjusting frame of AC Genera...

Page 39: ... cylinder block with soft brush and solvent Fig 42 Check whether there re damages or cracks on the topside of cylinder block or in the main bearing seat screw hole oil passage and internal cavity 2 Check the flatness of topside of cylinder block Measure the flatness of surface contacting the cylinder head gasket with the precision ruler and the thickness feeler The maximal warp tolerance is 0 05mm...

Page 40: ...oil film at this side of cylinder wall gets thinner by washing out and in the meantime the entrance of dust in air speeds up the abrasion of cylinder wall on the side of intake port When the temperatures of cylinder walls at front and rear ends of in line engine are low the abrasion is great Fig 45 Three Groups of Standard Cylinder Inside Diameters Printed on the Bottom of Cylinder BlockCylin der ...

Page 41: ...n forward and backward If the move occurs replace the whole set of piston and piston pin Fig 48 7 Detach the piston ring Fig 49 1 Remove the 2 compression rings with the piston ring expander 2 Remove the oil ring and the liner ring by hand The piston ring must be located in proper sequence 8 Remove the connecting rod off the piston press the piston pin out of the piston with the dedicated servicin...

Page 42: ...r of cylinder bore d If the oil film clearance is greater than the maximal value replace all the 4 pistons and re bore the 4 cylinders e Replace the cylinder block if necessary f In the case of using the new cylinder block make sure to use the pistons that have the same number marks as the dimension group marks printed on the cylinder block topside Fig 52 In this way to match the servicing dimensi...

Page 43: ...r fails the requirement check the oil film clearance and grind or replace the crankshaft if necessary 2 Check the cylindricity of each main shaft journal and connecting rod journal Maximal cylindricity 0 02mm If the measured cylindricity is greater than the maximal value replace the crankshaft If necessary grind the main journal or the connecting rod journal till the diameter is smaller than that ...

Page 44: ...maller 3 Bore and grind the cylinder to meet the calculated dimensions Maximal grinding 0 02mm Over grinding may damage the cylindricity of finished product Fig 57 Difference between the Upper and Lower Main Bearing Shell Fig 58 How to Mount the Main Bearing onto the Cylinder Block 1 Install the oil ring and the liner ring by hand 2 Install the 2 compression rings with the piston ring expander wit...

Page 45: ... the 2 thrust washers onto the No 3 main bearing cap with the oil duct outwards Fig 61 Mount the 5 bearing cap onto proper locations with the arrow marks forwards Assemble them according to the shown arrows and sequences Fig 62 2 Mount and screw on the 10 main bearing cap bolts with a thin layer of engine oil applied on the bolt screw according to the shown sequence Fig 63 by multiple and equal ac...

Page 46: ...e connecting rod caps onto the connecting rods a Match the connecting rod caps with the proper connecting rods according to the numbers b Install the connecting rod caps with the front end marks forwards Fig 66 Fig 63 Sequence to Screw on the Main Bearing Cap Fig 64 Check the Axial Clearance of Crankshaft with the plastic oil clearance gauge Fig 66 Have the Marks of Connecting Rod and Connecting R...

Page 47: ...th the dedicated servicing tools 16 Mount the oil filter 17 Mount the water pump 1 Put the new O ring onto the cylinder block 2 Mount the water pump with 3 bolts with the fastening torque of 14N m Fig 69 18 Install the mounted bracket at the right side of engine Mount the installation rack at the right side of engine with 3 bolts with the torque of 51N m 19 Assemble the adjusting frame of AC gener...

Page 48: ...the torque of 78N m c Check whether the clearance between the lower end of speed sensor and the tooth top of flywheel signal disc is 1 0 10mm with a bolt fastening sensor with the torque of 8N m Complete when mounting the power assembly Fig 70 Sequence to Fasten the Flywheel Nuts 44 ...

Page 49: ...form rotational flow It also features good exhaust and purge effect 4 The structure is relatively complicated there are four combustion chambers 16 valves double camshaft ten bearing holes 16 tappet holes water chambers with different shapes jet holes oil passage gear chamber eight intake exhaust ducts many bolt holes a lot of spacer plates and reinforced ribs Valve stem guide and valve seat that ...

Page 50: ...ve all carbon deposits in combustion chamber Fig 76 Pay attention not to scrape lower contact surface of cylinder head and cylinder block II Inspection Fig 72 Remove Valve Tappet Fig 73 Use long nose pliers to remove oil seal Fig 74 Use compressed air and magnet bar to remove valve spring seat head when engine is warmed up that is to say detach it when the engine is in cold state 2 Remove valve ta...

Page 51: ...eds the above mentioned maximum value replace the cylinder head 2 Check whether there is any crack Use dye penetrant to check Fig 80 whether there is crack in combustion chamber air inlet air outlet and the surface of cylinder head Replace cylinder head if any crack is found 4 Clean valve 1 Use scraper to eliminate carbon deposit attached on valve end 2 Use wire brush to eliminate fuel combustion ...

Page 52: ... valve guide to obtain Intake 0 025 0 058mm Exhaust 0 025 0 058mm 2 Max oil clearance Intake 0 08mm Exhaust 0 10mm If oil clearance is larger than the maximum value replace valve and valve guide Fig 79 Check planeness on three planes of cylinder head At cylinder block side At intake manifold side At exhaust manifold side Fig 80 Use dye penetrant to check whether there is crack in cylinder head Fig...

Page 53: ...the minimum value replace the valve 4 Check full length of valve Fig 86 Maximum full length Intake 87 60mm Exhaust 87 95mm Minimum full length Intake 86 40mm Exhaust 87 65mm If full length is less than the minimum value replace the valve length 5 Check abrasion on the end surface of valve stem and trim it If the end of valve stem is abraded use abrasive wheel to grind and trim the end or replace v...

Page 54: ...e met correct valve seat using the following method a If 1 0 1 4mm valve sealing belt on 45º seat surface is a bit high use 30º and 45º reamer to shape the valve seat Fig 90 Note assure valve stem valve seat Please assure that the trueness of valve seat and valve stem is 0 030mm b If 1 0 1 4mm valve sealing belt on 45º seat surface is a bit low use 60º and 45º reamer to shape the valve seat Fig 91...

Page 55: ... force when the length of spring is 31 7mm 160 8N If installation pulling force does not meet requirement replace valve spring 9 Check camshaft and bearing 1 Check radial run out of camshaft a Place the camshaft on a V block b Use a dial gauge to measure circumferential radial runout at middle journal Fig 96 specified maximum circumferential radial run out 0 03mm If circumferential radial run out ...

Page 56: ...measure journal diameter Fig 98 Journal diameter NO 1 Exhaust 24 949 24 965mm Other 22 949 22 965mm If journal diameter does not meet requirement check oil clearance 4 Check camshaft bearing Check whether the bearing has shellingout and ablation if the bearing is damaged replace the entire set of bearing cap and cylinder head Fig 99 Fig 100 Check free distance of camshaft gear spring Fig 101 Check...

Page 57: ... 000 31 025mm 2 Use micrometer to measure tappet diameter Fig 105 Tappet diameter 30 966 30 976mm 3 Calculate oil clearance Subtract measured tappet diameter from measured tappet pore diameter Standard oil clearance 0 015 0 055mm Maximum oil clearance 0 07mm If oil clearance is larger than the maximum value replace tappet Replace cylinder head if necessary 11 Check planeness of junction surface of...

Page 58: ...mm Max oil clearance of exhaust valve 0 058mm If the clearance is larger than the above maximum value replace valve and valve guide Operating procedure is 1 Heat cylinder head gradually to 80 100o C Fig 108 2 Use special servicing tool and hammer to slightly knock the valve guide out Fig 109 3 Use inside micrometer to measure pore diameter of guide installed on cylinder head Fig 110 Pore diameter ...

Page 59: ... 960 5 975mm Exhaust 5 960 5 975mm Guarantee standard oil clearance 1 Bend the strap on ventilation baffle upwards which prevents oil seal from sliding out 2 Use screwdriver to pry out oil seal Fig 113 3 Use special servicing tool and hammer to press in new oil seal Fig 114 4 Apply a thin layer of all purpose grease onto the edge of oil seal 5 Restore strap on ventilation baffle to its original po...

Page 60: ...ark plug guide on the cylinder head Fig 116 3 Use the standard pressing machine to press the guide of spark plug until standard protrusion distance of 46 8 47 6mm has been reached Fig 117 V Installation of cylinder head 2 Mount the air valve 1 Use specialized maintenance tool to press the new oil seal in Oil seal of intake valve is gray and wrapped with rubber while oil seal of exhaust valve is bl...

Page 61: ...o the cylinder block a Place the new cylinder head gasket onto the cylinder block in a correct direction of installation Fig 123 b Place the cylinder head onto the cylinder head gasket Make sure they are precisely matched Fig 118 Press in valve new oil seal with servicing tools Fig 120 Assemble valve and spring compo Fig 119 Difference between oil seal of intake and exhaust Valve Inlet Grey surfac...

Page 62: ...rding to shown sequence in Fig 125 with several equal operations with the torque of 29N m If bolt size does not meet specification it shall be replaced c according to shown sequence in Fig Tighten the bolts on the cylinder head again The torque is 95 3N m 5 Mount the intake camshaft 1 Fix the hex head of camshaft onto the bench clamp Be noted not to damage camshaft 2 Mount circlip for camshaft gea...

Page 63: ...e lubricating grease on the thrust positions of camshaft b Position the exhaust camshaft to make the dowel pin in an angle counter clockwise from the axle of camshaft In this position the peach tip of 1 and 3 cylinder cam can push the valve tappet in a balanced way Fig 129 c Remove all the old filling material remaining on the surface d Smear new filling material onto the exhaust camshaft bearing ...

Page 64: ...nto thrust position of intake camshaft c Engage the gears of intake camshaft with the gears of exhaust camshaft following the mounting mark on each gear Make sure not to confuse mounting mark with timing mark Fig 135 d When gears mesh with each other place intake camshaft onto the bottom hole of bearing seat e Install the four bearing caps onto their corresponding positions in arrow direction and ...

Page 65: ...f camshaft gears match When timing marks match two mounting marks are on the top as shown in Fig 140 7 Inspect and adjust the clearance of valves Rotate the camshaft to position the camshaft tip upward Inspect and adjust the valve clearance Valve clearance under cool condition Intake valve 0 15 0 25 mm Exhaust valve 0 25 0 35mm 8 Mount timing pulley of camshaft 1 Make sure that dowel pins of camsh...

Page 66: ...ley and keep a clean surface After mounting inspect whether the tension force between crankshaft timing pulley and camshaft timing pulley is normal 11 Inspect valve timing 1 Loosen the belt tensioner bolt Fig 144 2 Rotate the crankshaft for two cycles starting from the TDC of cylinder I and returning to the TDC after two circles Be noted to rotate clockwise 3 Inspect whether each pulley aligns wit...

Page 67: ...ylinder head 15 Mount cylinder headcover 1 Remove all old seal material 2 Fill the seal material onto cylinder head as shown in Fig 150 3 Mount the gasket inside the lower liner ring slot of cylinder head 4 Mount the cylinder head with four seal gaskets and locking nuts with a torque of 10 8 N m 16 Mount spark plug 17 Mount 2 water inlet connection flange 1 Put a new gasket onto the cylinder head ...

Page 68: ...l be mounted onto the air intake manifold with two bolts 20 Mount fuel injector and fuel delivery pipes 1 Smear a thin layer of gasoline onto the two new O rings and mount them onto the fuel injector Fig 154 2 Mount the four fuel injectors onto the delivery pipes when rotating them 3 Place the power resource union of injector upward 4 Mount the injector with four clips Fig 155 5 Mount two spacers ...

Page 69: ...ect the engine wire harness Fix the wire harness support with two nuts Fig 160 23 Mount water bypass hoses and fuel return hoses 1 Use two bolts to install water bypass hoses and fuel return hoses onto intake manifold with torque of 10 2 N m Fig 158 Fasten the bolt on the intake manifold that fixes the pipe Fig 159 Connection between the fuel hose and pipe Fig 155 Method of fixing injector onto th...

Page 70: ...20N m Fig 163 4 Connectors throttle position sensor 1 connector of ISC idle speed control valve 2 Fig 164 26 Mount water inlet port and its shield 1 Completely remove the old filling material in the water intake There shall be no impurities or oil stains 2 Fill the sealant into the slot on the shield Fig 165 Fig 160 Fixing engine wire support Fig 161 Connect fuel return hose to pressure regulator ...

Page 71: ...il Fig 169 4 Connect the high voltage wire 5 Adjust the ignition timing 29 Install water outlet pipe 1 Completely remove old seal material in the cylinder head and connection flange There shall be no impurities and oil stains on the surface 2 Smear the sealant into the slot of water outlet connection flange Fig 170 3 Use two bolts to mount the water outlet connection flange Fig 171 with torque of ...

Page 72: ...nnection of engine wire harness 1 Mount the wire harness support with bolts 2 Connect the following wires and clips a Connector of AC generator b Wire of AC generator c Connector of oil pressure switch d Clip of wires e Wires of AC compressor 35 Mount AC compressor belt 36 Mount water pump pulley and driven belt of AC generator 37 Filling engine oil 38 Filling engine coolant After assembling clutc...

Page 73: ...t track is designed on piston pin seat which permits the continuous suction of lubricant To achieve fine thermal conductivity heating surface on the piston top introduces the structure of smooth transition and a big transition circular is adopted to connect top plate and ring belt 1 Structural Characteristics of Piston Piston Pins and Piston Rings 1 Piston The main functions of piston are to under...

Page 74: ...d pin seat varies from 0 002mm to 0 013mm Such structure has the advantages of omitting copper sleeves and piston pin clamp rings reducing connect ing rod small end width and lengthening pin seat But connecting rod must be mounted at the temperature of about 100oC or be squeezed by press machine at the temperature of 40oC in cold state which will cause difficulties in disassembly 3 Piston ring Pis...

Page 75: ... 122 0 031mm center distance between the two bolt holes is 54 0 1mm diameter of the big end is 43 The section of the rod body is I shaped the big end of the connecting rod cap has a thickness of 22 The center distance of the JL481Q connecting rod 132 5 0 050mm center distance between the two bolt holes is 62 0 1mm diameter of the big end is 51 They will be processed after it is assembled with the ...

Page 76: ... assembly 4 Dismount the connecting rod from the piston see Section II Chapter II Section 2 Dismantling and Inspection of the Connecting rod and its Bearing Fig 181 Installation of the connecting rod bearing Fig 182 Assembling of the piston and the connecting rod Front end mark Recess Front mark Bulging 1 Assemble the piston and the connecting rod Fig 182 1 Paste engine oil on the piston pin and p...

Page 77: ...od Mechanism and Troubleshooting Fig 183 Installation of the piston and connecting rod assy 0 15 0 30mm 0 35mm 1 486 1 490mm 1 490 1 494mm 1 494 1 498mm 0 020 0 051mm 0 019 0 065mm 0 08mm 0 15mm 0 06mm 100mm 0 03mm 100mm Standard Max Standard Mark 1 Mark 2 Mark 3 Standard Increase by 0 25 Min Max Max Max Standard Min Axial play of the connecting rod Wall thickness at the middle of the Standard con...

Page 78: ...poor piston lubrication is likely to lead to ablation In such cases replace the entire set of piston assembly II Damage of the Piston Pin III Broken or Ablated Piston Ring Table 6 Among common faults with the piston pin are tubercular corrosion fleck and bending deformation due to wearing as well as deformation of out of round If the cylindricity of the piston pin is over 0 002mm and roundness is ...

Page 79: ...ing the connecting rod correcting instrument Check the connecting rod bolt Install the lock nut for the connecting rod bolt Check the lock nut by turning it to the end position with hand If the lock nut can not rotate flexibly measure the external diameter of the bolt with a vernier calipers Standard outer diameter is 8 860 9 00mm and min outer diameter is 8 6mm If the outer diameter is smaller th...

Page 80: ... receive the force from a connecting rod thus creating the torque rotating around its own axes Engine crankshaft is made of nodular cast iron installed entirely with support which has enhanced the rigidity and bending strength of crankshaft The diameter of MR479Q 5 main bearing journal is 48mm the diameter of 4 connecting rod journal is 40mm The diameter of JL481Q main bearing journal is 48mm the ...

Page 81: ... in a good bending strength and torsion rigidity Meanwhile thickness of crank arm is transited through the shoulder In order to relieve the crankshaft s weight and reduce the unbalanced properties of crankshaft rotating the shoulder of crankshaft adopts a big angle In order to reduce the stress centralization between cranks and main bearing journal and between crank and connecting rod journal R2 b...

Page 82: ...or dowel pin holes There are 5 mounting holes for flywheel and 1 hole for positioning the flywheel Revolving speed toothed disc installed on the outer peripheral of flywheel is interference fit with the flywheel The peripheral is positioned by dowel pin There are totally 60 2 teeth on revolving speed toothed disc and there is a T mark on the disc end face The T mark corresponds to the locating hol...

Page 83: ...ft with lifting action Fig 192 d Clean all the main bearing journals and main bearing shells e Check whether all the main bearing journals and main bearing shells have dents and flaws on the surface Fig 193 In case that the main bearing journal or main bearing shell are damaged replace the bearing shell When necessary grind the crankshaft f Mount the crankshaft onto the cylinder block pass the pla...

Page 84: ...earance 0 10mm If the oil clearance is larger than the maximum value replace the bearing shell When necessary grind or replace the crankshaft If the cylinder block parts are changed the standard clearance of bearing shell should be 0 015 0 045mm If standard bearing shell is used it is necessary to use those with the same number If the number of bearing shell cannot be determined it is possible to ...

Page 85: ...g Crankshaft 1 Install the main bearing a Align the protrude portion of main bearing upper harf with the recess on the cylinder block bearing seat while pushing 5 upper bearing shell through Fig 57 58 b Align the protrude portion of lower bearing shell with the recess on the main bearing cap while having 5 lower bearing shell pushed through Fig 59 2 Install thrust washer Fig 60 Place two crankshaf...

Page 86: ...ue Wall thickness of connecting rod bearing mm 1 5 0 010 0 015 1 5 0 005 0 010 1 5 00000 0 005 Connecting rod journal mm 48 00000 0 006 48 0 006 0 012 48 0 012 0 018 Connecting rod big end bore mm 51 0 006 0 51 0 012 0 006 51 0 018 0 012 Wall thickness of connecting rod bearing mm 1 5 0 010 0 014 1 5 0 006 0 010 1 5 0 002 0 006 Connecting rod journal mm 40 0 010 0 015 40 0 010 0 015 40 00000 0 05 ...

Page 87: ...ir it II Wear of Flywheel Working Face and Damages to Gear Ring 1 Normally when starting the engine the flywheel gear ring and starter pinion easily collide with each other or have poor engagement between the two teeth thus easily leading to wear and damages to the teeth a When the teeth of gear ring are worn on one side turn it over for further use The gear ring detaching or assemble needs heatin...

Page 88: ...eper etc Make up of valve train is shown in Fig 198 Chapter 6 Valve Train I Make up of Valve Train Section 1 Make up of Valve Train its Design Features Fig 198 Schematic Diagram of Valve Train Assy 1 Filling adjusting shim 2 Valve tappet 3 Spring retainer 4 Valve spring 5 spring seat 6 Valve guide bushing 7 Valve 8 Exhaust camshaft 9 Tension spring 10 Tensioner 11 Crankshaft timing pulley 12 Pulle...

Page 89: ...d closing of valves do not correspond to the top and bottom dead centers but in an earlier time for opening and a later time for closing In general different engines have different timing The best one is chosen according to the experiment results Once the timing is chosen the angle between the intake cam and the exhaust cam of the same cylinder and the marks of meshing engagement for each timing g...

Page 90: ...ing pulley is made from die casting of powder metallurgy tooth form hole and keyway are made at the same time without the requirement of machining On the parts there is V type timing mark When assembling and calibrating valve timing diagram it is necessary to align it with the timing mark on the housing of oil pump There are a total of 24 teeth on crankshaft timing pulley 2 Camshaft timing pulley ...

Page 91: ...le larger than wrap angle of intake cam buffer and the wrap angle of exhaust cam working section a little bigger than wrap angle of intake cam working section The MR479Q MR479QA cam base circle is 34mm in diameter intake cam lift is 7 81mm and exhaust cam lift 8 06mm The center of camshaft is a main oil passage Each journal has small holes leading to the main oil passage so as to lubricate each ca...

Page 92: ...le it facilitates the adjustment of the valve clearance The material used for tappet is low carbon alloy steel 4 Valve spring Engine uses a single spring cylindrical helical spring The spring is 3 2mm in diameter with a central diameter of 21 0 1mm and coiling wraparound ratio C 6 56 The precompression quantity of intake valve spring is 7 8mm and that of exhaust valve spring 7 5mm To keep the spri...

Page 93: ...re you need to make a mark during detaching See Fig 202 II Camshaft and bearing seat 1 Check the run out of camshaft If the radial run out is larger than the maximum replace the camshaft 2 Check the peach tip height of cam and if not up to the standard replace the camshaft 3 Check the camshaft journal If the diameter is not up to the standard check the oil film clearance 4 Check the cam bearing fo...

Page 94: ...amshaft timing belt is aligned with the U mark on the No 1 bearing cap Fig 205 4 Installing timing belt 2 Tensioner To check whether the belt tension pulley runs smoothly and flexibly When necessary replace it Measure the free length of tension spring Free length 36 9mm Measure the tension of the spring with the specified length The installing tension Length 43 6mm 34 38N If the tension is not up ...

Page 95: ...timing mark Fig 206 Otherwise you need to reinstall it Adjust the deflection of timing belt fig 148 and tighten the bolts of belt tensioner with the torque of 37N m Fig 207 Fig 205 Aligning Compression TDC Mark Fig 207 Fasten tensioner Fig 206 Check timing mark Table 10 V1 Common Servicing Data Servicing Data 6 000 6 018mm 11 000 11 027mm 11 050 11 077mm 87 5 0 10mm 87 8 0 15mm 86 95mm 87 35mm 44 ...

Page 96: ...ce when L is 31 7mm Tappet bore diameter Tappet diameter Oil film clearance axial clearance Journal oil film clearance Journal dia Circle run out eccentricity Camshaft peach tip height Base circle lift Camshaft gear tooth clearance Camshaft gear snap ring Free distance at end Standard Max Intake Exhaust Max Standard Max No 1 exhaust Others Max Standard Intake Exhaust Standard Intake Exhaust Standa...

Page 97: ...uide is proper or not If not ream it 6 If the valve can t be closed tight due to deformation replace valve seat ring 7 If valve spring breaks or losses elasticity it shall be replaced III Valve Seat Damage Common troubles of valve seat are scorching wearing and deformation Once any scorching spots pits or obvious wear ing signs are found in the valve seat it is necessary to ream or grind it if it ...

Page 98: ...lm on cylinder wall into the airflow when the pressure therein drops because the throttle is adjusted to decrease its flow rate 5 Improved performance under transition working conditions when multiport injection applied Multiport injection eliminates the interference from fuel films on intake manifold walls with control of air fuel ratio so the performance under transition working conditions will ...

Page 99: ...ng range for the used fuel when keeping compression ratio unchanged 11 Accurate measurement of fuel rate Carburetor shall carry out quantitative control of fuel rate in addition to various processing functions including atomization vaporization diffusion and mixing Its control accuracy is difficult to guarantee In gasoline injection system fuel pump and injector carry out fuel delivery while ECU d...

Page 100: ... of a permanent magnet and an armature On pump cover there are electric contact connector for outlet pipe and check valve Check valve is used to keep some residual pressure within the fuel system after the electric fuel pump stops running so that it restarts Without check valve the positive pressure fuel will flow back into the fuel pump and fuel tank resulting in system decompression so the fuel ...

Page 101: ...ilter mud forms 4 Fuel pressure regulator Fuel pressure regulator for multiport injection is mounted to the end of fuel distributor Its function is to keep invariable the pressure difference between within the fuel distributor and within the space fuel enters into i e intake manifolds i e fuel supply pressure intake pressure fuel Injection pressure pressure difference between interior and exterior...

Page 102: ...by active carbon granules in the carbon canister and then be preserved into the engine When the engine is running due to the vacuum in inlet manifold fresh air passes through the carbon canister and enters into the intake manifold with fuel previously adsorbed carried with it 1 Carbon canister an unit containing carbon granules and used to adsorb gasoline vapors 2 Control valve for carbon canister...

Page 103: ...t 5 Persons who hold no qualification certificate or who have never received any professional training are not eligible for ECU servicing 6 Have regular check on connectors of the hose to make sure that the connection is firm and accurate 7 Do not employ used cotter pins washers O rings and oil seals 8 You shall use 93 or above unleaded gasoline 9 When the engine is running you shall immediately s...

Page 104: ...ent shocks For any EFI part you shall be careful to handle it esp ECU 4 Be careful when locating the fault because of the great number of transistor circuits inside and even the slightest touch on any terminal will cause a number of faults 5 Do not open the ECU cover 6 When checking it on a rainy day you shall keep it away from water Also you shall prevent EFI parts and wires from water contact wh...

Page 105: ...et Force length 30cm 8 Fuel system 1 A large amount of gasoline will flow out when the high pressure fuel pipe is disconnected Therefore you shall follow the following instructions a Place a container under the connector b Slowly unscrew the fuel pipe connector c Detach the fuel pipe connector d Plug up the fuel outlet with a rubber plug See Fig 217 2 You shall fix one connection nut or connection...

Page 106: ... connection bolt after placing an appropri ate towel or container under the fuel delivery pipe 4 Install the fuel inlet hose and a special pressure meter onto the transmission pipe with three washers and a special connection bolt See Fig 222 The fastening torque is 29 N m 5 Wipe off the splashed fuel 6 Connect the cable for the battery s negative pole to it 7 Connect the terminals B and FP of the ...

Page 107: ...he cable of battery s negative pole and detach the special tools Prevent fuel splashing during the process 19 Connect the fuel inlet hose to the fuel delivery pipe with two new washers and the connection bolt The fastening torque is 29Nm 20 Finally check whether there is any fuel leakage Detaching the fuel pressure regulator See Fig 224 1 Remove the hose for vacuum sensor from the fuel pressure re...

Page 108: ...Fig 224 Detaching and separating fuel pressure regulator o ring Fuel pressure regulator Hose for vacuum sensor Fuel return hose 104 ...

Page 109: ...a forced ventilation hose for the crankcase See Fig 231 II Injector Examination Fig 229 Use a multimeter to examine the resistance between the injector s terminals New O ring Ohmmeter Examination on the car 1 Examine each injector s working condition Examine each injector s running sound and atomization 1 Use a stethoscope to check whether the engine running noise is normal when it is running or s...

Page 110: ... Detaching and disassembling injector and fuel delivery pipe O ring Fuel inter hose Washer Fuel pipe Linjector O ring Clip Spacer PVC hose PVC hose Lnjector terminal Fuel return hose Hose for vacuum sensor 106 ...

Page 111: ...o spacers for the intake manifold 3 Detach the four clips for the four injectors 4 Detach the four injectors from the fuel delivery pipe 5 Detach the O ring of each injector Examination after detaching 1 Examine each injector s injection capacity Fig 235 and Fig 236 When doing this the injector being examined shall be kept away from spark 1 Remove the connection bolt and two washers and remove the...

Page 112: ...e regulator See Fig 268d 7 Install an O ring onto the injector Fig 235 Assemble the pipe system for examining injectors Fig 236 Schematic diagram of measuring SST connect connect 8 Connect the special hose for maintenance to the injector 9 Place the injector into a measuring cylinder 10 Connect the terminals B and FP of the check connector with a special line for maintenance 11 Connect the cable f...

Page 113: ...ector can rotate smoothly Fig 238 Install components of injectors and fuel delivery pipe Upward Clip Press Rotate Fig 237 How to install injector Injector Installation 1 Install injectors and fuel delivery pipe 1 Smear a layer of gasoline onto two new O rings and mount them onto the injector 2 Rotate each injector to the left and right alternately in order to connect it to the fuel delivery pipe E...

Page 114: ...range between VC and E2 is 4 5V to 5 5V when the throttle is completely shut the voltage value range between VTA and E2 is 0 2V to 0 9V when the throttle is completely open the voltage value range between VTA and E2 is 4 0V to 4 8V III Examination of Throttle Body Fig 241 Examine resistances between various terminals of the throttle position sensor Fig 242 The voltage check circuit for VC E2 VTA E...

Page 115: ...control valve Fig 244 Remove the hose and cover of the air filter Fig 243 Detaching and disassembling throttle body SXE7130 1109221 Throttle Washer Valve chamber vent hose Bypass hose for water cootant Connecter of ISC Vawe Hose and cover for the air fiter Connector of the thralfle positon sensor 111 ...

Page 116: ...l engine coolant 5 Detach the hose of air filter from the throttle body and remove it along with the air filter cover 4 Remove the throttle body 1 Remove the connector of the throttle position sensor and the connector of the idling speed control ISC valve See Fig 245 2 Remove the two bolts and the two nuts as shown in Fig 246 and disconnect the throttle body from the intake manifold 3 Remove the t...

Page 117: ...nnecting wires and ECU 4 Switch off the ignition and remove the plug for the idling control valve Switch on the ignition and measure the voltage valve between the plug 2 of the idling speed control valveand the ground wire See Fig 250 The voltage valve range specified is 9V to 14V 5 Remove the special connection wire from the check connector Detaching 1 Remove the throttle body 2 Remove the ISC va...

Page 118: ...eter Ohmmeter storage battery EFI main relay Ohmmeter No trgger Trigger Trigger Fig 253 The voltage check circuit for RSO E01 EFI No 1 15A Battery Main Fuse 30A IG2 AM1 EFI main relay EFI NO 2 10A Engine ECU EFI NO 1 15A 30A Battery Main EFI Main Relay EF2 NO 2 10A IG2 Idle Regulator B ROS E01 1 3 Engine ECU AM1 3 Check whether the ISC valve can open close and semi open automatically within 0 5 se...

Page 119: ...to the engine s working condition enabling the fuel vapor to be absorbed into the intake manifold for burning with the mixture within the cylinder So this system serves to effectively control HC emission without affecting the engine normal running The schematic diagram of the evaporative emission control system is as shown in Fig 259 Apply voltage to the terminal 1 and 3 of the battery Check wheth...

Page 120: ... a multimeter to check whether there is a connection between its terminals If not so you shall replace the VSV valve The resistance between its terminals should range from 27ohm to 33ohm when the ambient temperature is 20 C See Fig 260 3 Examine the grounding of the VSV valve Use the multime ter to check whether there is connection between its terminal and the valve body If so you shall replace th...

Page 121: ...h high voltage gas Inspect whether the alternator output voltage or current is normal when you replace sensor in finding fault VII Examination of Intake pressure temperature sensor Pressure sensor see Fig 264 intake pressure temperature sensor performance curve see Fig 265 Symptom of fault flame out poor idle Fig 261 Examine the grounding of VSV valve Fig 263 Examine the air flow after being power...

Page 122: ...ig 269 The voltage check circuit for THW E2 Simple measurement method Temperature sensor Removing the joint place the multimeter at ohm gear and connect 2 terminals respectively to 1 pin and 2 pin of sensor and rated resistance at 20o C is 2 5kΩ 5 and other corresponding resistance values could be measured according to the characteristic curve in above drawing Analog method could also be applied i...

Page 123: ...g the resistances and voltages at the ECU wires connectors 1 Examine the ECU voltage 1 Switch off the ignition take out the ECU plug and then switch on the ignition 2 Measure the voltage between B and E1 See Fig 273 the voltage should be from 9V to 14V If it does not fall into the range please check the fuse and EFI main relay Note the battery s voltage must be 11V or above The reference voltages ...

Page 124: ...ing ECU diagnostic signal output NC NC NC A C switch signal input The voltage is 12v when operating Electronic load signal input The voltage is 12v when operating Electronic load signal input The voltage is 12v when operating NC Phase sensor signal input E ECU e15ron ground 2 E ECU connects the ground when operating E ECU connects the ground when operating E ECU ignition ground 1 NC E ECU connects...

Page 125: ...centration in the mixture closer to the theoretical air fuel ratio Its error rate is less than 0 25 When the engine s working condition worsens it will adopt the open loop control method in order to avoid overheat caused by the catalytic reaction Fault phenomena related to oxygen sensor include unstable idling speed high fuel consumption and excessive exhaust The examination method is as follows 1...

Page 126: ...ct thereby solving the inconsistency between power fuel consumption and exhaust contamination Catalytic bed in catalytic converter is the carrier for catalytic agent which is rare earth metal such as platinum rhodium or palladium These catalytic agents are able to convert carbon monoxide and hydrocarbon into carbon dioxide and water and furthermore to convert nitrogen oxides and carbon monoxide in...

Page 127: ...ay Open loop relay Gasoline pump Starting signal Manual shift Starting relay Battery Starter Fuse Ne signal 1 Shut off the ignition and remove the ECU plug 2 Put on the ignition and use a multimeter to measure the voltage between the ECU s FC terminal and the ground wire See Fig 279 which should range from 9V to 14V If not so you shall examine the power supply to the ECU 3 Under normal voltage if ...

Page 128: ... 4 Evaporative Emission Positive Crankcase Ventilation Control System 1 Purpose of Evaporative Emission Positive Crankcase Ventilation Control System This system s components and layout are shown in Fig 259 and Fig 281 Vacuum solenoid valve for evaporative emission control Positive crankcase Ventiletion valve Active carbon filtration To reduce contamination of the atmosphere by harmful gases leake...

Page 129: ... damage hoses connectors washers etc shown in Fig 283 If so you shall troubleshoot them III Examination of Evaporative Emission Control System 1 Visually examine whether there is any deformation crack leakage or damage in the fuel tank tank cap gasket pipes or connectors Fig 284 If necessary you shall repair or replace the tank cover Fig 283 Examine hoses connectors washers etc visually Fig 282 Bl...

Page 130: ...ster Before doing this shut off other pipes positioned above the carbon canister and blow the air through the fuel tank pipe into it Note never attempt to cleanse the active carbon canister otherwise active carbon may probably leak out 4 Install the active carbon canister 3 Check the vacuum solenoid valve Refer to Chapter 7 Section 4 of the Evaporative Emission control 126 ...

Page 131: ...tion system is equipped with a constant current control device which can enable a strong current to pass through the ignition coil within a short time 2 Ignition timing control For the purpose that the engine can effectively convert thermal energy into mechanical energy we hope that the highest combustion pressure occurs when its crank rotates to some point after reaching the top dead center From ...

Page 132: ... path The primary current depends on the battery s voltage the primary winding s resistance and poweron time When the primary current is cut off a self induction electrodynamic potential is created within the primary winding and under this electrodynamic potential a secondary induction electrodynamic is generated within the secondary winding which is proportional to the winding ratio of the second...

Page 133: ... i e from the rubber bushes on them Note do not pull the wire so as not to damage the core body inside the high voltage wire See Fig 287 2 Use a multimeter to measure the resistance of the high voltage wire See Fig 288 The maximum resistance should be 25 000ohm If the measured resistance exceeds this maximum value you shall examine the terminals of the high voltage wire If necessary you shall repl...

Page 134: ...ge If so you shall replace it 3 Adjust the clearance between electrodes i e carefully bend the side electrode so as to obtain an appropriate clearance between electrodes See Fig 291 The correct clearance between electrodes is 0 8 0 1mm JL481 Q MR 481QA clearance between electrodes is 1 0 05mm 4 Use a 16mm spark plug socket wrench to mount the spark plug the torque to screw it tightly is 18Nm and r...

Page 135: ...and breakdown air pressure are low Spark plug only makes spark but doesn t ignite Symptom of fault Engine cannot start Common cause of fault burning due to high current damaged by external force Attention for service It s forbidden to test ignition function with short circuit jump fire from damaging electronic control Simple measurement method Place the digital multimeter in position ohm two conne...

Page 136: ...essure and then passes through the engine oil filter for thorough elimination of very small metal scraps and feculence Afterwards the finely filtered oil enters into the main oil duct within the cylinder block On the main oil duct the engine oil pressure switches are tandem placed so as to issue warning when the lubrication oil pressure is too low The engine oil entering into the main oil passage ...

Page 137: ...en the engine oil consumption will easily increase The engine oil passage diagram for engine s lubrication system is shown in Fig 295 As a reliable rotor type engine oil pump with a simple structure the engine oil pump adopted by engine pumps oil by volume change of internal and external rotors Its driving rotor has 10 teeth and its driven rotor has 11 teeth The two rotors centers have an offset e...

Page 138: ...ine oil filter structure is shown in Fig 297 Lubricating oil firstly flows in through holes scattered around the engine oil filter and then enters into the filter element along the sidewall The lubricating oil filtered by the filterelement goes into the central main pipe through small neck bush holes and then flows into the main oil gallery within the cylinder block If the filter element is comple...

Page 139: ...ad hood there are two forced interfaces placed one of which is connected to the air filter and the other is connected to the resonant chamber of the intake manifold Such design can produce a vacuum difference between the air filter s rear end and the resonant chamber of the intake manifold which will bring a negative pressure for the crankcase Thus the fresh air can flow into the crankcase mix wit...

Page 140: ...d the oil strainer 1 Drain the engine oil 2 Remove the timing belt 3 Remove the idle wheel and the tension spring 4 Remove the crankshaft timing gear 5 Remove the oil dipstick and the guide tube See Fig 299 1 Remove the installation bolt 2 Pull out oil dipstick and guide tube 3 Remove the O ring from guide tube 6 Remove the oil sump 1 Remove the 19 bolts and 2 nuts See Fig 300 2 Insert a special s...

Page 141: ...e standard clearance between the driven rotor and the case body ranges from 0 100mm to 0 180mm the maximum allowable clearance between them is 0 20mm If the real clearance exceeds the maximum valve you shall replace the whole set of rotors If necessary you shall also replace the oil pump compo 2 Examine the clearance between the two rotors Use a feeler gauge to measure the clearance between the to...

Page 142: ...he pressure relief valve Install the pressure relief valve the spring and the limiter into the hole of the oil pump body and use a clasp pincers to mount the clasp Installation 1 Oil pump installation 1 Mount a gasket onto the cylinder body 2 Engage the keyslots of the oil pump s driving rotor with the crankshaft s big teeth and then slide the oil pump in See Fig 309 3 Examine the side clearance o...

Page 143: ...the idling speed while at the speed of 3 000r min it should range from 294KPa to 539KPa 6 Remove the oil pressure meter and reinstall the oil pressure switch 1 Remove the oil pressure meter for measurement 2 Smear adhesive onto the No 2 and No 3 circles of screw thread of the oil pressure switch See Fig 313 3 Use a special maintenance tool to install the oil pressure switch The torque to screw it ...

Page 144: ...4Nm 2 Fill the engine oil The engine oil tank s capacity is as follows when the drained engine oil is filling or the engine oil filter has been replaced its capacity is 3 0L when the engine oil filter is not replaced its capacity is 2 8L when it is a dry oil sump its capacity is 3 5L 3 Install the engine oil filler cover 4 Restart the engine and check whether there is any engine oil leakage 5 Exam...

Page 145: ...ystem Possible reasons and treatments are as follows 1 Dirty engine oil This will lead to blocked engine oil filter or bypass valve And in this case you shall replace the engine oil and the filter 2 Too small clearance of main crankshaft bearing connecting rod bearing or camshaft bearing You shall examine these clearances If so you shall reselect the corresponding bearing or polish their journals ...

Page 146: ...e over high pressure within the cylinder head cover along with fresh air failing to flow smoothly within the PCV system In addition the main reason for engine oil fleeing out is that the pressures within the crankcase and the cylinder head hood are too high thereby causing increased gap between sealing part and sealed part and decreased sealing part elasticity The fact that the part where the engi...

Page 147: ...c radiator Radlator function of the engine However it is important to make adequate cooling If being under cooled malfunctions like reduction of inlet air volume incom plete combustion inflammation caused by knock surface inflammation etc will occur If being overcooled work temperature of lubrication oil will be lowered which will increase the vicosiity of lubricant The increase of lubricant visco...

Page 148: ... located inside the body of water intake end interconnected with cylinder s jacket The upper end of rod 4 is fixed on support 3 while its lower end is inserted into rubber boot 5 Both rubber sheet 5 and body1 is filled with wax 7 If coolant temperature is lower than 80 C wax will be solidified and valve 6 will be pressed to close via spring 2 Thus coolant will directly flow into cylinder s cooling...

Page 149: ...there is still a small amount of coolant to bypass through It is of great magnitude Table 18 Fig 319 Wax single Valve thermostat a b c Specification of Thermostat Model of thermostat Temperature in C valve begins to opened Temperature in C valve fully opened Valve lift stroke mm Wax type 82 2 95 8 Fig 318 Installation of thermostat 1 Housing 2 Spring 3 Bracket 4 Push rod 5 Rubber boot 6 Valve clos...

Page 150: ...e coolant temperature is higher than 101 C 3 C temperature detect switch cuts on fan motor works and fan high shift rotates If coolant temperature is lower than 95 C 2 C temperature detect switch cuts off fan high shift stops working The technical parameters are shown in Table 20 With regard to the M7 9 7 EFI system in JL481Q MR481QA car the basic principle of the rotation and operation of its coo...

Page 151: ...ction 2 Inspection and Maintenance of Cooling System 1 Cleaning and Maintenance of Radiator 1 Inspect whether there are any deformation on the sealing surface If any defects are found the parts shall be repaired or replaced 2 Inspect the edge part of parts If any defects are found such parts shall be repaired 4 Inspection on radiator cover 1 Inspect the sealing gasket see Fig 323 If bent or deform...

Page 152: ...opening pressure is 58 5kPa while standard value is 73 5 102 9kpa If malfunction is found such valve shall be replaced The valve opening temperature is within the range between 80 C 84 C 1 3L 1 5L and 78 C 80 C 1 6L 1 8L while valve lift is higher than 8mm at the temperature of 95 C If the temperature does not meet the above requirements replace the thermostat If deformation is found repair shall ...

Page 153: ...repair is required if any failure occurs V Water filling and Air Exhaust If under cooled parts like cylinder and cylinder head will be over heated Thus replenishment of coolant is needed Most troubles come from the following three 1 Engine overheat caused by under cooling If engine is overheated when coolant volume is adequate it is possibly caused by pump failure loose pump belt fan failure or th...

Page 154: ...g the axis of the aperture The projection will take the pressure plate to rotate through the clutch cover when the flywheel rotates The pressure spring is a diaphragm spring made of stamped high grade spring steel sheet Near the center there are radial cuts which form elastic lever The outer rim of the diaphragm is pressed on the pressure plate to make pressure plate flywheel and driven plate pres...

Page 155: ...th bolt The release bearing is pressed into the bearing sleeve The release sleeve is put on the transmission input shaft The release fork is a lever with pivot in the middle To pull the release fork can pull out the pressure plate through release bearing to release pressure plate s pressure on Driven plate Assy The release mechanism is shown in Fig 330 Fig 329 Clutch Friction Plate Fig 330 Clutch ...

Page 156: ...al is shown in Fig 332 The pedal install height can be adjusted via adjusting bolt The pedal install height is 181 5 mm III Structure of Clutch Operating Mechanism The disassembled structure of clutch is shown as Fig 333 Section 2 Clutch Troubleshooting 1 Clutch Detaching Fig 333 Clutch parts 1 Bolt with washer 2 Locking plate 3 Clutch release lever 4 Bushing 5 Clutch release fork 6 Torsion spring...

Page 157: ...friction surface when the warpage of pressure plate or flywheel exceeds 0 2mm the scratch exceeds 0 5mm or the unevenness exceeds 0 12mm The total grinding amount should not exceed 1 0 1 5mm or the pressure plate or flywheel needs replace 2 Check the diaphragm spring inner end for wear corrosion or breakage Replace the diaphragm spring when there are severe wear When the inner ends of the diaphrag...

Page 158: ... Abnomal shape replace 3 Check the clutch friction plate for wear and axial run out the allowed wear limit is 0 33 mm rivet depth the allowed axial run out limit is 1 34mm Mount the clutch plate on new input shaft before measurement of axial run out see Fig 336 4 Check the release bearing for smooth running turn the release bearing with hand Fig 337 and apply axial pressure Check if there are abno...

Page 159: ...operation evenly starting from the position near dowel pin c Smear lithium base grease on the spline of clutch plate assy 2 Check disengaging pawl of diaphragm spring in clutch pressure plate assy for height consistence Make some adjustment if necessary Fig 342 343 a Check Allowed height variation limit 0 7mm b Adjustment 2 Maintenance Clutch operating mechanism needs periodical inspection and mai...

Page 160: ...d the relative slip surfaces between release bearing and release sleeve Fig 345 4 Install bushing dust proof cover torsion spring and clutch release lever 5 Install bolt with washer locking plate Fig 346 Tightening Torque 29 4 39 2 Nm 6 Check the operation of release bearing and release fork run the clutch release fork about 40 50 times and check the position A on release bearing circlip Replace w...

Page 161: ...install height 1 Release the nut on spacing bolt adjust it to appropriate position for pedal install height to reach specified value 2 Tighten pinch nut 3 Adjust clutch cable Fig 352 1 Pull the cable boot lightly and check the spacing 2 The protruding stopper on the spacing cushion should be in the groove of the nut 3 Adjust cable jacket to make sure the distance between nut and spacing cushion is...

Page 162: ...ning Replace the clutch plate when the wear exceeds working limit If the plate lining is slippery and hardened the friction coefficient will go down and affect the normal torque transfer therefore the clutch plate lining should be grinded with sandpaper or replaced if it is not repairable During vehicle drive don t place your foot on clutch pedal which may cause the clutch half coupled and lead to...

Page 163: ... of pressure plate and flywheel gets warped or friction plate assy gets warped 4 Clutch friction plate splined bore hub is severely worn the transmission input shaft deforms and band 5 The friction plate has viscous substance on the surface Engine bracket gets loosen and engine bracket rubber gasket ages 6 Operating mechanism and extention rod bush and pin gets loosen or stagnant Check replace Che...

Page 164: ...not start and there is no signs of ignition or with signs of ignition it is still impossible to start There are many causes that lead to start failure such as faults in the start system ignition system gasoline injection system and engine mechanical failure etc 1 Starter Does Not Rotate or Cannot Drive the Engine to Rotate or Rotation Is Slow 1 Symptom of fault starter does not rotate or rotates i...

Page 165: ...must be damaged replace it if the test lamp does not illuminate then check whether main fuse EFI relay fuse ignition switch and ECU terminal are normal if not repair or replace it d If fuel pressure is too low fuel injection volume must be too small for the engine to start Now check whether fuel filter in the oil passage is clogged or not whether safety valve of fuel pump is damaged whether fuel p...

Page 166: ... position due to mechanical abrasion aging or fault of control circuit now replace the idle control valve repair control circuit and eliminate the fault g If data of water temperature sensor is not accurate it might lead to too small fuel injection check the water temperature sensor according to standard data and adjust the data h Time lag of vacuum pressure sensor is large response is not sensiti...

Page 167: ...k Check ignition system Works Normal Check spark gap Measure fuel pressure Check cylinder pressure Measure intake pressure water temperature and intake temperature sensor Replace Clogged Works Too low Check pressure adjuster petrol pump and filter Check cylinder pressure Normal Repair control circuit Check fuel pressure Check injector Does not work Check injector Check electric fuel pump and its c...

Page 168: ...ting or replacement e Untight air intake and exhaust valve ineffective piston ring etc tend to cause lower compression pressure of the cylinder now repair intake exhaust valve and seat or replace them replace the piston ring if it is ineffective 4 Diagnosis and troubleshooting Procedure for engine start difficulty Fig 356 Engine is hard to start Check whether air filter is clogged or not Clean or ...

Page 169: ...lug and combustion chamber l Water temperature switch or thermostat fails m Oxygen sensor EGO aging n Ignition timing incorrect o Check valve fails 3 Diagnosis procedure of less powerful engine Fig 357 2 Poor Deceleration 1 Symptom of fault Idle operation is normal but when loosening accelerator pedal abruptly during driving for deceleration engine flameout often occurs 2 Cause of fault and elimin...

Page 170: ...p fuel pressure adjuster gas filter Replace Replace Replace Check whether throttle could be opened completely Check whether air filter is clogged or not Check whether throttle position sensor fails or not Check ignition timing Check water temperature switch thermostat Check whether vacuum pressure sensor fails or not Check fuel pressure Check oxygen sensor Check injector Replace spark plug ignitio...

Page 171: ...leshooting Procedure for Poorly Accelerated Engine Poor acceleration Check ignition timing Restore Check tightness of intake system Clean or replace Clogg Check whether air filter is clogged or not Check whether throttle position sensor fails or not Check pressure of oil passage system Check whether fuel injection of the injector is normal at idle speed with heavy load Repair or replace Replace Ad...

Page 172: ...replace it h Compression pressure of the cylinder too low repair it i Pressure of oil passage too low repair it j Air filter clogged clean eliminate or replace it k Poor atomization of injector there are leaking blocking or large difference between injections repair it 3 Fault diagnosis procedure Fig 359 Fig 359 Fault Diagnosis and Troubleshooting Procedure for Instability and Flameout at Idle Spe...

Page 173: ...to is cold but after the auto is warmed up it still maintains quick idle speed which causes the idle speed to be excessively high 2 Cause of fault and elimination a Initial idle speed is not adjusted well readjust it b Pressure of oil passage in the system is high make adjustment c Water temperature sensor is defective repair or replace it d Water temperature switch or thermostat fails repair or r...

Page 174: ...is case it is necessary to replace oil seal or bushing to return to normal condition Item Symptom Cause Elimination method Insufficien t coolant Defective radiator Defective radiator hose Defective radiator hose band Defective head gasket Crack on cylinder body Defective seal of water pump Antifreeze not replaced Defective thermostat Replace antifreeze Replace the thermostat Clogged cooling pipe P...

Page 175: ...between intake exhaust valve and their bushing is mainly caused by jamming between the valve and its bushing valve cannot be closed repair bushing or replace it 5 Abnormal noise is caused by untight close between valve and valve seat engine cannot work normally now grind the valve for good fitting otherwise replace it 3 Abnormal noise in gear is mainly caused by too large backlash due to abrasion ...

Page 176: ...is too large Piston ring lines up Piston ring is locked Elasticity of piston ring is insufficient Airtightness between piston and cylinder wall is poor Knock occurs when the engine is cold Knock occurs when the engine is warm Knock occurs no matter the engine is cold or warm Depth and width of main bearing oil bath is inaccurate or oil pressure is insufficient so cylinder wall is not lubricated we...

Page 177: ...tor while the surplus energy is supplemented to the battery When the generator is overloaded the battery supplies power Structure is shown in Fig 360 1 Rotor Assy The rotor with the excitation coil runs together with the shaft as a whole part It is composed of the iron core excitation coil collector ring and fan SMA car series is equipped with three phase silicon rectifier alternator whose voltage...

Page 178: ...ll be put in the V block or placed in the lathe for correction If necessary replace the rotor assy 3 Armature winding check Fig 362 The open circuit malfunction of the armature winding can be checked by the R 1 of the multi meter When checking connect the two rods with any two of the wires of the armature winding the circuit shall be connected If the value is infinity it indicates an open circuit ...

Page 179: ...y terminal voltage is below 12 6V charge the battery immediately Charge with 1 10 of the capacity for 3 5 hours and terminal voltage shall reach between 13V 14V other wise recharge it Keep the battery fully charged and charge once a month during the storage period 1 Structure of Lead Battery Section 2 Battery 1 Short circuit in the battery the partition board of battery after long use will be subj...

Page 180: ...and replace it if necessary 2 Low charging current The insufficiency of generation volume and too small charge current causes a severe shortage of electricity in battery This phenomenon mainly originates from a malfunctioning voltage regulator Malfunctions include an electricity regulation out of order and failure to establish a working voltage due to the lack of adequate excitation electricity Th...

Page 181: ...made by pressing bronze powder and graphite 2 Control switch It applies the magnetic switch using the ignition switch to control the magnetic switch on the starter so as to switch on or off the circuit and help the starting of engine 3 Driving Mechanism The driving mechanism is composed of overrunning clutch and pinion When the starter rotates and the magnetic switch is switched on the pinion will...

Page 182: ...r is ignited and run if the switch is still in the start position the ring gear will draw and drive the pinion to rotate Then under the effect of overrunning clutch the starter pinion starts to skid around on motor shaft so as to prevent the starter armature winding from high speed rotation driven by the engine Loosen the ignition switch and keep the winding power off with magnetic force disappear...

Page 183: ...is not enough power in battery and serious deficiency of electrolyte You should refill the distilled water 2 There is loosening or oxidation between the positive power line of battery and wiring terminal Clear away the pole oxides and fasten the positive power wires to the terminals 3 Ignition switch open circuit Replace ignition switch 4 Open circuit in the wires from ignition switch to pull in w...

Page 184: ...issue in electronic control of engine fuel system is the electronic control of fuel quantity actually electronic control of excess air coefficient λ ECU controlsλthrough control of fuel injection amount When engine works ECU gets airflow information from the sensor and determines fuel injection amount through some calculations thereby enables excess air coefficient of gas mixture to reach preset v...

Page 185: ...ode immediately Its feedback signal is the signal of knocking sensor Therefore it is also a closed loop control on the whole ECU unit electronic control unit to receive various information from sensors After processing and analysis it sends control impulse to individual actuator serving as nerve center in the electronic control system Hardware of electronic control unit ECU can be divided into thr...

Page 186: ...m inductive sensor are processed in a special circuit to suppress interfering impulses 2 Microcomputer Microcomputer of engine ECU is integrated into a single chip and consists of 1 Microprocessor Also called Central Processing unit CPU it mainly consists of three parts a Arithmetical logic unit b Register block c Controller 2 System bus Internal bus performs data transmission between individual p...

Page 187: ...the ECU controls pump relay through output stage of electric fuel pump according to operating conditions at that time and then controls on off of electric fuel pump 4 Other output stages Output stages to control idle speed control valve solenoid valve of carbon canister and failure indicator etc Idle speed controls in both Model MR479Q MR479QA and Model MR481QA JL481Q belong to closed loop control...

Page 188: ...D system SMA s engine which applies the engine management system is high powered car s gasoline engine and succeed in matching test of GB IV with OBD system emission standard in 2007 Cooling fan controlled by Engine electronic system is different in car type The control method includes 1 ECU transmits the signal to control cooling fan at the same speed for example MR6370 car type etc 2 ECU transmi...

Page 189: ... cable coil the permanent magnet rotates to bring the slide block into rotation The angular position of the slid block determines the opening of the bypass air passage of the actuator so that the bypass volume can be regulated The electronic controller determines the angular position of the slide block by changing the ratio of air occupation of the pulse signal sent to the performer thus determini...

Page 190: ...y is a micro motor The steel stator is a multiphase coil winding and the rotor is a permanent magnet When electrifying stator coil the permanent magnetism stator will rotate towards corresponding direction on the impact of the electromagnetic power Since stator and helix shaft are screw thread contact stator s angular rotation will transform into helix shaft s rectilinear motion While stator rotat...

Page 191: ...urement unit generated through 100 thick film technology Being sealed in a ceramic base it contains air of a given volume and a reference pressure of about 20kPa A pressure resistant thick film tension meter points to the air bubble and protected with glass to avoid damage by hazardous medum The tension meter with its high measurement sensitivity measurement factor approx 12 linearity and no hyste...

Page 192: ...chni cal parameters are shown in Table 27 Fig 370 Sketch of Principle of the Water Temperature Sensor Technical Parameters of DS S TF Pressure Sensor Technical Parameters of TF W Water Temperature Sensor Temperature sensor characteristic curve Resistance 10 4 10 3 10 2 40 0 40 80 12 C 0 C 5280 6570 20 C 5280 6570 40 C 5280 6570 60 C 5280 6570 Pressure range Input voltage Mass Vibration resistance ...

Page 193: ...rs of the speed sensor 7 Ignition Coil Structure of the ignition coil The ignition system adopts a double ignition coil and its form and circuit are shown in Fig 372 and Fig 373 Operating principle of the ignition coil The two ignition coils directly controlled by the computer generate a high voltage alternatively The secondary side of either ignition coil is connected to the spark plugs of the tw...

Page 194: ...hamber the diaphragm displaces to move away the valve ball assembly on the diaphragm to return part of fuel in the fuel chamber to the fuel tank so that the fuel pressure of the system may keep constant Refer to Table 30 for the technical parameters 8 Pressure regulator Fig 374 9 Phase sensor Fig 375 Technical Parameters of ZS K2 x 2 Ignition Coil Technical parameters of DR2 pressure regulator a O...

Page 195: ...e Hall voltage so that its condition becomes on The technical parameters of the phase sensor are shown in Table 31 Table 31 10 Throttle position sensor Throttle valve angular position sensor a potentiometer with a linear characteristic curve converts the opening angle of the throttle into a voltage signal namely the rotational angle of the throttle is proportional to the voltage The rotor of the s...

Page 196: ...Depending on different working conditions of the engine ECU changes the ratio of air occupation of the pulse signal sent to the solinoid coil thus changing the opening Furthermore valve opening is also influenced by P the differ ence of pressures at the two ends of the valve Pu Ps The technical parameters are shown in Table 34 Fig 377 Schematic Diagram of the Knock Sensor 1 Vibration mass under th...

Page 197: ...gen contents of the two sides of the sensitive element differ little Therefore the potential produced is also very low about 0 1V In the case of dense mixed gas the exhaust contains Technical parameters of TEV2 carbon canister control valve Fig 378 Schematic Diagram of the oxygen sensor 1 Cable 2 Disk washer 3 Lower insulation bushing 4 Protective sleeve 5 Angle wire 6 Heating rod 7 Angle gasket 8...

Page 198: ...ers are given in Table 36 Technical parameters of PG 1 phase sensor Table 36 Table 37 Table 38 Fig 381 Structural sketch of the electrical fuel pump Technical parameters of EKP 13 5 electric fuel pump Technical parameters of 1 3L 1 5L electric fuel pump characteristic parameter Technical parameters of 1 8L electric fuel pump characteristic parameter dimension Mass Life cycle Mileage installation t...

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