Engine Turns Over But Does Not Start - Isuzu NHR 4J Series Workshop Manual

00 – 4 SERVICE INFORMATION

3. ENGINE TURNS OVER BUT DOES NOT START

Checkpoint
Engine stop
mechanism
FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP
Fuel
Fuel piping
Fuel filter
Fuel system
Fuel feed pump
FUEL IS BEING DELIVERED TO THE INJECTION PUMP
Fuel
Fuel system
Injection nozzle
Injection pump
Possible cause
Defective fuel cut solenoid valve
Fuel tank is empty
Clogged or damaged fuel lines. Loose fuel
line connection
Fuel filter overflow valve does not close
Clogged fuel filter element
Air in the fuel system
Defective feed pump
Use of the wrong fuel
Water particles in the fuel
Air in the injection pump
Injection nozzle sticking
Injection nozzle injection starting pressure
too low
Improper spray condition
Defective fuel injection nozzle resulting in the
fuel drippage after fuel injection
Defective injection pump control rack
operation
Injection pump plunger worn or stuck
Injection pump drive shaft seizure or other
damage
Injection pump governor spring seizure
Correction
Replace the fuel cut solenoid valve
Fill the fuel tank
Repair or replace the fuel lines
Retighten the fuel line connection
Repair or replace the fuel filter
overflow valve
Replace the fuel filter element or the
filter cartridge
Bleed the air from the fuel system
Repair or replace the feed pump
Use the correct fuel
Change the fuel
Bleed the air from the fuel system
Adjust or replace the injection nozzle
Replace the delivery valve
Repair or replace the injection pump
control rack
Replace the injection pump plunger
assembly
Replace the injection drive shaft
Replace the injection pump governor
spring