Insufficient Power - Isuzu NHR 4J Series Workshop Manual

Checkpoint
Injection pump
(Cont'd)
Valve clearance
Compression pressure
Checkpoint
Air cleaner
Fuel
Fuel filter
Fuel feed pump
Injection nozzle
Fuel injection pipes
Possible cause
Injection timing improperly adjusted
Insufficient injection volume
Defective idle spring
Defective governor lever operation
Regulator valve improperly adjustment
Broken plunger spring
Worn plunger
Worn cam disc
Valve clearance improperly adjusted
Blown out cylinder head gasket. Worn
cylinder liner.
Piston ring sticking

3. INSUFFICIENT POWER

Possible cause
Clogged air cleaner element
Water particle in the fuel
Clogged fuel filter element
Defective fuel feed pump
Injection nozzle sticking
Injection nozzle injection starting pressure
too low
Improper spray condition
Fuel injection pipes damaged or obstructed
SERVICE INFORMATION 00 – 7
Correction
Adjust the injection timing
Adjust the injection volume
Replace the idle spring
Repair or replace the governor lever
Adjust or replace the regulator valve
Replace the plunger spring
Replace the plunger assembly
Replace the cam disc
Adjust the valve clearance
Replace the related parts
Correction
Clean or replace the air cleaner
element
Replace fuel
Replace the fuel filter element or the
fuel filter cartridge
Repair or replace the fuel feed pump
Replace the injection nozzle
Adjust or replace the injection nozzle
Replace the fuel injection pipes