MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
384
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Chapter VI Fuel System
Section I General
Attention:
When performing the maintenance work of fuel supply system, bear the following items
in mind:
(1) When the fuel supply system is working, you should disconnect the earthing wire of storage batteries
unless the test needs the storage batteries for power supply.
(2) A (Grade B) dry chemical fire extinguisher shall always be prepared near the work site.
(3) Replace all the removed fuel pipes and fittings with the same new ones.
(4) Before repairing any parts of the fuel supply system, firstly release the pressure in the pipeline.
(5)
Do not repair the fuel supply system, if you have not read this User’s Guide and checked the
drawings and technical materials related with repair.
GW4D20/GW4D20B turbocharged diesel engine can be equipped with a DELPHI, BOSCH, or
XINFENG electronic fuel injection system.
1. Components of Fuel Supply System
A GW4D20/GWD20B turbocharged diesel engine employs high-pressure common-rail fuel supply
system.It primarily consists of sensor group, ECU, actuator group and the harnesses connecting with
these parts.There are different sensors, such as camshaft position sensor, crankshaft position sensor,
knock sensor, coolant temperature sensor, turbocharger pressure sensor, high-pressure fuel rail
pressure sensor and air flow sensor.
The actuator part is composed of low-pressure fuel circuit and high-pressure fuel circuit.The
low-pressure fuel circuit contains fuel tank, fuel delivery pipe, fuel filter, fuel delivery pump and the
low-pressure area of high-pressure fuel pump.The high-pressure fuel circuit contains high-pressure fuel
rail, high-pressure fuel pipe, fuel injector, and the part of high pressure area in high-pressure fuel
pump.The electronic control unit (ECU) automatically controls the fuel supply process of
GW4D20/GW4D20B turbocharged diesel engine.For the arrangements of the fuel supply pipelines of
DELPHI, BOSCH and XINFENG common-rail systems, see Fig. 6-1-1, Fig. 6-1-2 and Fig. 6-1-3
respectively.
Fig. 6-1-1
Arrangement for fuel supply pipeline of DELPHI common-rail system
Fuel tank
Manual fuel
pump
Fuel filter
Fuel
return
tee
High-pressure fuel
pump assembly
High-pressure fuel
rail assembly
Fuel injector assembly
Electronic control unit
