Isuzu 4JB1T - User Manual

SERVICE INFORM
ATION 00 – 3
1.
HARD STARTING
1. STARTER INOPERATIVE
Checkpoint Possible cause Correction
Loos
e battery cable terminal poor
connections due to rusting
Clean and/or retighten the battery
cable terminal
Batter
y discharged or weak Recharge or replace the battery
Battery
F
an belt loose or broken Adjust or replace the fan belt
F
usible link Fusible link shorted Replace the fusible link
Star
ter switch Defective starter switch or starter relay Replace the starter switch or the
Starter relay
Def
ective magnetic switch or starter relay Repair or replace the magnetic switch
Starter m
otor
Defective starter motor Repair or replace the starter motor
2. STARTER MOTOR OPERATES BUT ENGINE DOES NOT TURN OVER
Loos
e battery cable terminal Clean and/or retighten the battery
cable terminal
Poor
connections due to rusting Recharge or replace the battery
Batter
y discharged or weak Recharge or replace the battery
Battery
F
an belt loose or broken Adjust or replace the fan belt
Def
ective pinion gear Replace the pinion gear
Def
ective magnetic switch Repair or replace the magnetic switch
Star
ter
Brush wear, Weak brush spring Replace the brush and/or the brush
spring
Engine
Piston, crank bearing seizure, or other
damage
Repair or replace the related parts

Isuzu 4JB1T Specifications

General

Displacement	2.8 L (2771 cc)
Bore x Stroke	93 mm x 102 mm
Fuel System	Direct Injection
Cooling System	Water-cooled
Aspiration	Turbocharged
Weight	Approx. 230 kg (dry)

Summary

1. HARD STARTING

1. STARTER INOPERATIVE

Troubleshooting for a starter that does not function.

2. STARTER MOTOR OPERATES BUT ENGINE DOES NOT TURN OVER

Diagnosing issues when the starter motor runs but the engine is not turning.

3. ENGINE TURNS OVER BUT DOES NOT START

FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP

Problems related to fuel not reaching the injection pump.

FUEL IS BEING DELIVERED TO THE INJECTION PUMP

Issues when fuel is delivered, but the engine still doesn't start.

4. QUICK-ON START SYSTEM

GLOW PLUGS ARE RECEIVING POWER

Troubleshooting glow plugs when they are receiving power.

GLOW PLUGS ARE NOT RECEIVING POWER

Troubleshooting glow plugs when they are not receiving power.

10. ABNORMAL ENGINE NOISE

1. ENGINE KNOCKING

2. GAS LEAKAGE NOISE

3. CONTINUOUS NOISE

11. ENGINE COOLING TROUBLE

Engine overheating

Troubleshooting causes of engine overheating.

13. TURBOCHARGER

1. ENGINE HAS LESS THAN NORMAL POWER

Troubleshooting low engine power related to the turbocharger.

LUBRICATING SYSTEM

FUEL SYSTEM

COOLING SYSTEM

ENGINE CONTROL

QUICK-ON START II SYSTEM (4 JB1; 4 JB1 T; 4 JB1 TC only)

QUICK-ON START III SYSTEM (4 JG2 only)