Doosan D439E - Page 159

D439E Service Manual 4. Fuel system
157
Engine hesitation or poor acceleration
Check fuel system
NG
Check injection timin
g
• Supply pump
• Fuel filter
• Fuel
p
ressure re
g
ulator NG
Check fuel pressure
OK
• Injector state
NG
Check injector
OK
• Wiring connection
• Power to ECU
1. Fusible link
2. Fuse
3. Control relay
• Engine coolant temperature
sensor
• Injection signal circuit
1. Injector wiring
2. ECU
NG
Check en
g
ine control system
OK
Check clutch or brake
• Clutch slip
• Brake slip
OK
Check sir cleaner element Clean or replace element
Self dia
g
nosis chec
k
Trouble code
• Use Hi-scan
OK
OK
NG
NG