MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
106
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fuse cable
connector
Looseness or bad contact of the fuse
cable
Clean and fasten the fuse cable.
Rotation speed
sensor
Damage of the rotation speed sensor
Replace the rotation speed sensor.
Fuel (diesel)
No
fuel
in
the
fuel
tank,
or
inappropriate fuel
Add fuel or apply the motor diesel
(specified by CB 19147-2009).
(continued)
Checking Item and
Part
Cause of Malfunction
Troubleshooting
Air left in the fuel
system
Fuel system not exhausted completely
Exhaust the air in the fuel system
through the fuel filter.
Low pressure oil
circuit
Blockage or leakage of the low
pressure oil circuit
Repair the low pressure oil circuit,
replace the damaged parts of low
pressure oil circuit and exhaust the air
in the fuel system.
High pressure fuel
pump and high
pressure fuel rail
Unable to build up the pressure of the
high pressure fuel rail
Check the high pressure fuel pump,
high pressure fuel rail and pressure
sensor; replace defective parts if
necessary.
Fuel injector
electromagnetic valve
Fuel injector
electromagnetic valve not
working or bad contact
Check the working status of the fuel
injector electromagnetic valve and
replace the fuel injector if necessary.
Electronic control
unit (ECU)
Abnormal work of the electronic control
unit (ECU)
Replace the ECU, and input the
currently used injector code when
replacing the ECU.
Preheat system
Abnormal work of the glow plug in
winter
Replace the glow plug, and check the
glow plug control unit.
16. Diesel Engine Rotating but Unable to be Started
Checking Item and
Part
Cause of Malfunction
Troubleshooting
Fuel pipe system
Blockage or damage of the fuel pipe;
looseness of the fuel pipe connector
Repair or replace the fuel pipe, and
refasten the fuel pipe connector.
Overlow pressure of
the low pressure oil
circuit
(1) Overflow valve of the fuel filter
cannot be closed
(2) Blockage of the fuel pipe or the fuel
filter element
(1) Repair or replace the fuel filter
overflow valve.
(2) Check the fuel pipe and replace the
fuel filter element or the filter core.
Fuel system
Air left in the fuel system
Exhaust the air in the fuel system
through the fuel filter.