Doosan D439E - Page 157

D439E Service Manual 4. Fuel system
155
Hard to start the engine. (cranking is possible)
OK
• Wiring connection
• Power to ECU
1. Fusible link
2. Fuse
3. Control relay
• Engine coolant temperature
sensor
• Intake air temperature sensor
• Injection signal circuit
1. Injector wiring
2. ECU
NG
Self diagnosis
Trouble code
•
Use Hi
-
scan
Check injector
• Leakage
• Fuel line
• Fuel filter
• Fuel pump
No trouble code
Trouble code
NG
Check fuel supply to injector
• Fuel pressure
• Fuel in the tank
• Oil filler cap
• Oil level gauge
• Vacuum hose connection
Fuel pressure check (comparison
between
target and actual
values)
• Supply pump
• Fuel filter
• Fuel pressure regulator
Engine control system check
OK
OK
NG
NG