6 T - 4 E M I S S I O N C O N T R O L S Y S T E M S
be drawn into the intake manifold and thus less fuel
enrichment during idle or deceleration conditions (Fig.
2
b).
Vacuum for the spark advance is taken from a point
above the carburetor’s throttle plate (throttle in closed
position). At engine idle, this port is above the throttle
blade and no vacuum is available. Without vacuum, the
timing is retarded. As the throttle is opened, the port is
uncovered providing vacuum spark advance for normal
operation (Fig. 3b).
Cooling System
With the introduction CCS, higher engine coolant
temperatures were necessary; therefore, a 195°F coolant
thermostat was employed - previous thermostat were
rated at 180°F. Hotter running engines help reduce
hydrocarbon emissions by providing more complete
vaporization and also by reducing quench area. Quench
area is the area of each cylinder that is near the cylinder
wall. The cylinder walls are relatively cold in comparison
to the center of the cylinder bore. As the air fuel ratio
enters the chamber in its vaporous state, the mixture that
expands against the relatively cool cylinder walls
condenses to a certain extent. As the ignition flame
travels from the spark plug. It fails to ignite these
condenseed vapors near the cylinder walls. By increasing
the coolant temperature the size of the quench area is
reduced and thus the ignition flame can consume more
of the fuel thus reducing emission content (Fig. 4b).
Thermostatically Controlled Air Cleaners
All CCS systems incorporate a “ thermostatically
controlled air cleaner”. The thermostatic air cleaner
system (referred to as ThermAC System) is designed to
keep air entering the carburetor at approximately 100°F.
when underhood temperatures are less than 100°F. By
keeping the air at 100°F. or more, the carburetor can be
“leanly” calibrated to reduce hydrocarbon emission,
minimize carburetor icing, and improve engine warm-up
characteristics.
The thermostatically controlled air cleaner system is
composed of a special air cleaner and a heat stove. The
heat stove is nothing more than a sheet metal case
IDENTICAL ENGINES IDLING AT 700 RPM
INITIAL TIMING 8° B.T.D.C.
Relatively little air flow past
carburetor throttle plate which
is in nearly closed position.
INITIAL TIMING 4° B.T.D.C.
Larger throttle plate opening
is needed to allow more air
into the fuel to achieve 700 R.P.M.
Fig. 3b—Schematic of "Ported" Spark Advance
Fig. 2b—Relation of Tinning to Exhaust Emission
Fig. 4b—Cylinder Quench Area
surrounding the exhaust manifold that traps the heat
generated from the manifold and uses it to heat the air
going to the carburetor. The air cleaner primarily
consists of a body, filter element, sensor unit, vacuum
diaphragm assembly, damper door, and connecting
vacuum hoses and links (Fig. 5b).
The body and filter element resemble a conventional
snorkel type air cleaner. The sensor unit is mounted in
the body on the clean air side of the filter. The sensor
unit regulates (depending upon the temperature of the
air passing by it) the amount of vacuum supplied to the
vacuum diaphragm. The vacuum diaphragm (depending
on the amount of vacuum supplied to it by the sensing
unit) opens the damper door allowing heated air from
the heat stove to enter the cleaner and shuts off the
passage for ambient air. The damper door is fully open
(all warm air) at
8
inches of mercury and fully closed
(ambient air only) at
6
inches of mercury or less. The
vacuum signal measured at the diaphragm assembly will
not be the same as actual engine vacuum as the
thermostatic control valve in the sensor unit provides a
controlled vacuum leak for regulation of the supply
ADVANCED
OFF-IDLE
RETARDED
CARBURETOR
IDLE POSITION
INTAKE
MANIFOLD
VACUUM
DISTRIBUTOR VACUUM
ADVANCE
WATER
JACKET!
QUENCH
FLAME TRAVEL
QUENCH ARE.
WATER
LIGHT DUTY TRUCK SERVICE MANUAL
Содержание Light Duty Truck 1973
Страница 1: ......
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Страница 39: ...HEATER AND AIR CONDITIONING 1A 13 Fig 14 Heater Wiring Diagrams LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 53: ...HEATER AND AIR CONDITIONING 1A 27 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 115: ...LIGHT DUTY TRUCK SERVICE M A N U A L HEATER AND AIR CONDITIONING 1A 89...
Страница 123: ...BODY 1B 3 Fig 6 Typical 06 Van LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 149: ...BODY 1B 29 Fig 84 Body Mounting 06 Fig 85 Body Mounting 14 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 171: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 2 Frame Horizontal Checking Typical FRAME 2 3...
Страница 173: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 4 10 30 Series Truck Frame FRAME 2 5...
Страница 174: ...2 6 FRAME LIGHT DUTY TRUCK SERVICE MANUAL Fig 5 Underbody Reference Points G Van...
Страница 177: ...LIGHT DUTY TRUCK SERVICE MANUAL G 10 20 C 10 P 10 30 Fig 2 Front Suspension C P K Typical FRONT SUSPENSION 3 3...
Страница 185: ...FRONT SUSPENSION 3 11 Fig 16 Toe out on Turns LIGHT DUTY TRUCK SERVICE MANUAL...
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Страница 229: ...REAR SUSPENSION AND DRIVELINE 4 5 Fig 13 Rear Spring Installation C K Models LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 266: ......
Страница 310: ...5 44 BRAKES C MODELS G MODELS P MODELS Fig 77 Parking Brake System LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 351: ...ENGINE 6 15 Fig ID Sectional View of Eight Cylinder Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 375: ...EN G IN E 6 39 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 376: ...6 4 0 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 377: ...ENG IN E 6 41 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 378: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 37L K Series Engine Front Mount 6 42 ENG INE...
Страница 379: ...E N G IN E 6 43 FRONT MOUNT REAR MOUNT Fig 38L G Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 400: ...6 6 4 ENG INE LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 401: ...ENG IN E 6 65 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 402: ...6 6 6 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 403: ...E NG IN E 6 67 Fig 36V C Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 410: ......
Страница 423: ...EN G IN E C OOLING 6K 13 Fig 16 Overheating Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 424: ...6 K 1 4 ENG INE COOLING Fig 17 Coolant Loss Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 455: ...ENGINE FUEL 6M 31 Fig K13 Accelerator Controls P30 42 454 Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 456: ...6M 32 ENGINE FUEL Fig K15 Accelerator Controls G Van L 6 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 492: ......
Страница 506: ...CEC PLUNGER IS EXTENDED Fig lid Vacuum Advance Diagram Six Cylinder Engine 6T 14 EMISSION CONTROL SYSTEMS...
Страница 512: ...Fig 18e Vacuum Advance Diagram V8 Engine...
Страница 515: ...EMISSION CONTROL SYSTEMS 6T 23 Fig If Six Cylinder A I R System LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 516: ...6 T 2 4 E M IS S IO N CONTROL SYSTEMS LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 517: ...E M IS S IO N C O N TR O L SYSTEM S 6T 25 Fig 4f Diverter Valve Vent Valve LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 528: ......
Страница 540: ...6 Y 1 2 ENGINE ELECTRICAL Fig 16b Battery Installation C K Series LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 572: ...6Y 44 ENGINE ELECTRICAL Fig 25i V 8 Spark Plug Wire Installation LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 590: ......
Страница 592: ...7M 2 CLUTCHES MANUAL TRANSMISSIONS VIEW B Fig la Clutch Linkage Assy C K Models LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 593: ...CLUTCHES MANUAL TRANSMISSIONS 7M 3 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 594: ...7M 4 CLUTCHES MANUAL TRANSMISSIONS Fig lc Clutch Linkage Assy P Models LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 598: ...7M 8 CLUTCHES MANUAL TRANSMISSIONS LIGHT DUTY TRUCK SERVICE MANUAL...
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Страница 656: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 19M Drive Range Low First Gear Typical 7A 14 AUTOMATIC T R A N S M IS S IO N...
Страница 662: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 22M LI Range Manual First Gear Typical 7A 20 AUTOMATIC TRANSMISSION...
Страница 668: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 25M Reverse Range Typical 7A 26 AUTOMATIC T R A N S M IS S IO N...
Страница 739: ...FUEL TANKS AND EXHAUST 8 9 Fig 15 Filler Neck and Vent Hose Van LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 740: ...8 10 FUEL TANKS AND EXHAUST Fig 16 Fuel Feed and Return Pipes Front C K LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 743: ...FUEL TANKS AND EXHAUST 8 13 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 744: ...8 14 FUEL TANKS AND EXHAUST LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 746: ...8 16 FUEL TANKS AND EXHAUST Fig 2 5 Fuel Feed Pipe Front P 105 4 2 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 760: ...8 30 FUEL TANKS AND EXHAUST Fig 40 Exhaust Pipe P Models LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 761: ...FUEL TANKS AND EXHAUST 8 31 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 763: ...FUEL TANKS AND EXHAUST 8 33 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 766: ......
Страница 781: ...STEERING 9 15 OIL PRESSURE OIL RETURN PORT VALVE BODY Fig 21 Left Turn Position LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 832: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 106 Power Steering Pump Mounting Typical 9 66 STEERING...
Страница 833: ...PUMP ASSEMBLY STEERING GEAR TYPICAL SMALL V8 TYPICAL LARGE V8 STEERING 9 67...
Страница 860: ...9 94 STEERING LEAKAGE AREAS Fig 133 Power Steering Gear Leakage LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 861: ...STEERING 9 95 Fig 134 Power Steering Pump Leakage LIGHT DUTY TRUCK SERVICE MANUAL...
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Страница 886: ...11 10 CHASSIS SHEET METAL LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 891: ...ELECTRICAL BODY AND CHASSIS 12 5 LIGHT DUTY TRUCK SERVICE MANUAL...
Страница 897: ...ELECTRICAL BODY AND CHASSIS 12 11 Fig 14 Instrum ent Cluster Assembly C K Models LIGHT DUTY TRUCK SERVICE MANUAL...
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