
Fig. 356 Diagnosis and Elimination Procedure for Engine Start Difficulty
(3) Fault analysis and troubleshooting
a. Firstly conduct self-diagnosis for fault, check whether
there is any fault code, if there is, find cause according to
the code;
b. If it is difficult to start for cold auto and easy for warm
auto, check whether water temperature sensor or intake
temperature sensor is faulty;
c. If it cannot start quickly in warm auto condition, pressure
release in fuel pressure system is too quick, repair or
replace it;
d. If spark is too weak, check the general high voltage coil,
branch high voltage wire, spark plug gap and whether there is
accumulated carbon in spark plug etc. After the fault is
located, proceed with repair, troubleshooting 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 replace
Clogged
No
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Replace
Repair start signal circuit
Check ignition timing
Dismantle and check the engine
Check cylinder pressure
Replace ECU and test again
Check start switch signal
Check water temperature sensor and intake temperature
Repair electric petrol
pump, petrol filter and
fuel pressure adjuster
etc
Check idle control valve
Check fuel pressure
Check vacuum pressure sensor
Repair or replace
Abnormal
Too low
Abnormal
Replace
Adjust
Abnormal
Inaccurate
164
Содержание JL481Q
Страница 1: ......
Страница 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Страница 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Страница 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Страница 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Страница 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Страница 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Страница 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...
Страница 21: ...17 Fig 13 Exterior Feature of JL481Q Engine Power Me N m Torque Pe Kw ge g kwh Fuel Consumption Ratio ...