Isuzu 4JB1 User Manual

SERVICE INF
ORMATION 00 – 11
8. DA
RK EXHAUST SMOKE
Checkpoint Possible cause Correction
Air
cleaner Clogged air cleaner element Clean or replace the air cleaner
element
Inj
ection nozzle Injection nozzle injection starting pressure
too low
Improper spray condition
Adjust or replace the injection nozzle
F
uel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing
Def
ective delivery valve resulting in fuel
drippage after fuel injection
Replace the delivery valve
Inj
ection pump
Excessive injection volume Adjust the injection volume
9. OIL PRESSURE DOES NOT RISE
Checkpoint Possible cause Correction
Engine oil
Improper viscosity engine oil.
Insufficient engine oil
Replace the engine oil
Correct the engine oil volume
O
il pressure gauge or
unit
Oil pressure indicator
light
Defective oil pressure gauge or unit
Defective indicator light
Repair or replace the oil pressure
gauge or unit
Replace the indicator light
O
il filter Clogged oil filter element Replace the oil filter element or the oil
filter cartridge
Relief
valve and by-
pass valve
Relief valve sticking and/or weak by-pass
valve spring
Replace the relief valve and/or the by-
pass valve spring
Clogged oil pum
p strainer Clean the oil pump strainer
O
il pump
Worn oil pump related parts Replace the oil pump related parts
Roc
ker arm shaft Worn rocker arm bushing Replace the rocker arm bushing
Cam
shaft Worn camshaft and camshaft bearing Replace the camshaft and the
camshaft bearing
Cr
ankshaft and
bearings
Worn crankshaft and bearings Replace the crankshaft and/or the
bearings

Isuzu 4JB1 Specifications

General

Brand	Isuzu
Model	4JB1
Category	Engine
Language	English