MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
390
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 6-1-16 XINFENG High-pressure Fuel Rail
Assembly
Fig. 6-1-17 Installing the High-pressure fuel
rail assembly
Fig. 6-1-18 DFI1.5 Fuel Injector Assembly
(DELPHI Common Rail System)
Rail pressure sensor: it provides the pressure
parameters of common rail system (rail pressure
control part).
Rail pressure range: 1800-2200 bars
2.4.2 BOSCH High-pressure Fuel Rail
For the high-pressure fuel rail of BOSCH system, see
Fig. 6-1-15.
2.4.3 XINFENG System High-pressure Fuel Rail
For the high-pressure fuel rail of XINFENG system, see
Fig. 6-1-16.
Precautions for Using High-pressure Fuel Rail of
XINFENG System:
(1) When you are running the system, the
high-pressure fuel pipe connector at each part shall not
be loosened to avoid damage, since the fuel pressure
in the rail pipe may reach 1500 bar.
(2) The rail pipe must not be welded.
(3) Make sure that the connector rubber ring of rail
pressure sensor is complete, and avoid the water
shock.
(4) Pressure release will be started to ensure the
system safety, when the pressure of common-rail pipe
is higher than the safe pressure (1800 bar ± 50 bar) of
system..It is a normal phenomenon that a part of the
hot fuel at this time flows out of the fuel return
connector of safety valve.The safety valve closes after
the pressure is released and the system restore to the
normal working status.If the safety valve is under the
―opened‖ state for a long time, it shall be stopped and
the system shall be checked and repaired.
2.4.4 Installing the High-pressure Fuel Rail
(1) To ensure the cleanness of high-pressure fuel rail,
its protective cover shall not be detached before the
installation.
(2) Fit a high-pressure fuel rail and 2 hexagon flange
bolts (M8×30) to the cylinder cover and tighten them
with required torques. See Fig. 6-1-17.
Tightening torque for the fastening bolts of
high-pressure fuel rail:
23 N•m ± 3 N•m
2.5 Fuel Injector
The fuel injector functions to start at the scheduled time
according to the ECU control and inject fuel into the
cylinder for combustion.
2.5.1 DFI1.5 Fuel Injector
The GW4D20/GW4D20B turbocharged diesel engine
having a DELPHI common-rail system is provided with
a DFI1.5 fuel injector. See Fig. 6-1-18.The fuel injector
can realize multiple injections within quite a short
time.Under the electronic control, the heat produced in
Rail pressure
sensor
Fuel inlet
Safety valve
High-pressure
fuel rail
Fuel return
connector
Fuel inlet pipe
of high-pressure
fuel rail
Fuel injector
feeder
High-pressure
fuel rail
Nozzle spring
Coil
Control
valve
spring
Outer
edge filter
C2I code
Nozzle and
needle valve
Casing
Valve body
Transition plate
Adjusting
gasket
Fuel return
connector
Connector