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Isuzu N-Series. Manual - part 297

International Service & Parts

Tokyo, Japan

WORKSHOP MANUAL

N-SERIES

ENGINE 4H SERIES

SECTION 6

SERVICE INFORMATION 00-1

ENGINE 4H SERIES

SECTION 00

SERVICE INFORMATION

Contents

TROUBLESHOOTING .......................................... 00-2

MAIN DATA AND SPECIFICATIONS ................. 00-15

Main Data and Specifications .......................... 00-15

SERVICE STANDARD........................................ 00-25

SERVICING ........................................................ 00-39

FIXING TORQUE................................................ 00-56

Cylinder Head, Head Gasket and Head Cover ... 00-56
Crankshaft, Flywheel, Damper Pulley, Connecting
Rod and Oil Pan .............................................. 00-58

SPECIAL TOOLS ................................................ 00-67

Special Tools ................................................... 00-67

LUBRICATING SYSTEM..................................... 00-69

General Description ......................................... 00-69

00-2 SERVICE INFORMATION

TROUBLESHOOTING

Hard Starting

1. Starter Inoperative

2. Starter Motor Operates But Engine Does Not Turn Over

3. Engine Turns Over But Does Not Start

Checkpoint

Possible cause

Correction

Battery

Loose battery cable terminal
Poor connections due to rusting

Clean and/or retighten the battery cable
terminal

Battery discharged or weak

Recharge or replace the battery

Fan belt loose or broken

Adjust or replace the fan belt

Fusible link

Fusible link shorted

Replace the fusible link

Starter switch

Defective starter switch or starter relay

Replace the starter switch or the starter
relay

Starter motor

Defective magnetic switch or starter relay

Repair or replace the magnetic switch

Defective starter motor

Repair or replace the starter motor

Checkpoint

Possible cause

Correction

Battery

Loose battery cable terminal
Poor connections due to rusting

Clean and/or retighten the battery cable
terminal

Battery discharged or weak

Recharge or replace the battery

Fan belt loose or broken

Adjust or replace the fan belt

Starter motor

Defective pinion gear

Replace the pinion gear

Defective magnetic switch

Repair or replace the magnetic switch

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

Checkpoint

Possible cause

Correction

Engine stop mecha-
nism

Defective fuel cut solenoid valve

Replace the fuel cut solenoid valve

Fuel is Not Being Delivered to The Injection Pump

Fuel

Fuel tank is empty

Fill the fuel tank

Fuel piping

Clogged or damaged fuel lines
Loose fuel line connection

Repair or replace the fuel lines
Retighten the fuel line connection

Fuel filter

Fuel filter overflow valve does not close

Repair or replace the fuel filter overflow
valve

Clogged fuel filter element

Replace the fuel filter element or the filter
cartridge

Fuel system

Air in the fuel system

Bleed the air from the fuel system

Fuel feed pump

Defective feed pump

Repair or replace the feed pump

Fuel is Being Delivered to The Injection Pump

Fuel

Use of the wrong fuel

Use the correct fuel

Water particles in the fuel

Charge the fuel

Fuel system

Air in the injection pump

Bleed the air from the fuel system

SERVICE INFORMATION 00-3

4. Quick-on Start System

Injection nozzle

Injection nozzle sticking

Replace the injection nozzle

Injection nozzle injection starting pressure
too low
Improper spray condition

Adjust or replace the injection nozzle

Injection pump

Defective fuel injection nozzle resulting in
the fuel drippage after fuel injection

Replace the delivery valve

Defective injection pump control rack oper-
ation

Repair or replace the injection pump con-
trol rack

Injection pump plunger worn or stuck

Replace the injection pump plunger
assembly

Injection pump drive shaft seizure or other
damage

Replace the injection drive shaft

Injection pump governor spring seizure

Replace the injection pump governor
spring

Check point

Possible cause

Correction

Glow plug indicator
light does not turn on

1. Defective Fusible link wire

Replace the fusible link wire

2. Broken indicator light fuse

Replace the indicator light fuse

3. Defective indicator bulb

Replace the indicator light bulb

Preheating system
dose not work

1. Defective fusible link wire shorted

Replace the fusible link wire

2. Defective glow plug relay connector

Replace or Repair glow plug relay connec-
tor

3. Defective glow plug connector

Replace or Repair glow plug connector

4. Defective quick-on start timer connec-

tor

Replace or Repair quick-on start timer
connector

Preheating time to long
or to short

1. Defective thermo switch include defec-

tive wiring harness

Replace thermo switch

2. Defective glow plug

Replace glow plug

3. Defective timer unit

Replace timer unit

Checkpoint

Possible cause

Correction

Content .. 295 296 297 298 ..