Isuzu 4LC1 - Troubleshooting Engine Issues; Engine Start Failure Troubleshooting

TROUBLESHOOTING 105
SECTION 6
TROUBLESHOOTING
Engine does not start
Starter does not run
Check battery
Battery in
discharging
(Charge)
Engine
Fuel system Fuel injected
Fuel injected
Check
preheating
circuit
Poor
operation
of glow
plug
control
resistance
(Replace)
Check
injection
timing
Abnormal
(Adjust)
Check nozzle
Defective
(Repair or
replace)
Note: “Bring it to a specialty shop” means that defective parts of the injection pump
and electricals must be brought to a specialty shop for repair. (This note is
applicable to all the following procedures.)
Check engine stop
solenoid return
Check solenoid
Stuck solenoid or
poor operation
(Repair or replace)
Defective injection
pump (Bring
it to a specialty
shop for repair)
Normal
operation
of glow
plug
control
resistance
OK
No fuel
injected
Check if fuel
comes
to fuel pump
Check for air
mixing
Air mixed
(Retighten it,
replace
packing, bleed
air)
Check fuel
filter
Clogged
(Clean)
Check
compression
ratio
Low
compression
ratio
Defective
valve, spring,
gasket, etc.
(Overhaul)
Check starter switch
Defective
(Replace)
Check magnetic
switch
Defective
(Replace)
Check starter bush
Poor contact
(Repair or
replace)
Defective starter
(Bring it to a specialty
shop for repair)
Check wiring
Loosened
connector or
broken wire
(Retighten or
replace with
new wiring)
Engine starts but
does not run
continuously.
Air mixed in
fuel pump
Retighten,
replace
packing,
bleed air
Disordered
idling
Adjust
idling
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
(
*
)
★
(
*
)
Starter runs but does
not start