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TROUBLESHOOTING

175

SECTION 10

TROUBLESHOOTING

TABLE OF CONTENTS

ITEM PAGE

Hard starting .................................................................. 177

Unstable idling ................................................................. 181

Insufficient power .............................................................. 184

Excessive fuel consumption ...................................................... 188

Excessive oil consumption ....................................................... 190

Overheating ................................................................... 191

White exhaust smoke ........................................................... 193

Dark exhaust smoke ............................................................ 194

Oil pressure does not rise ........................................................ 195

Abnormal engine noise .......................................................... 197

Table of Contents3
General Information4
General Repair Instructions5
Notes on the Format of this Manual5
General Information7
Main Data and Specifications9
Standard Bolt10
Tightening Torque Specifications10
- Tightening Torque Specifications11
- Flanged Head Bolt11
- Special Parts Fixing Nuts and Bolts12
- Cylinder Head Cover, Cylinder Head, and Rocker Arm Shaft Bracket12
- Timing Gear Case, Flywheel Housing, Camshaft, and Timing Gear14
- Cooling and Lubricating System15
- Intake and Exhaust Manifold16
- Engine Electrical17
- Fuel Injection System18
Maintenance20
- Engine Serial Number21
- Injection Pump Identification21
- Lubricating System21
- Main Oil Filter21
- Model Identification21
- Fuel Filter22
- Fuel System22
- Cooling System25
  - Operating Test25
  - Thermostat25
- Valve Clearance Adjustment26
- In-Line Type Injection Pump27
- Injection Timing27
- Compression Pressure Measurement29
  - Engine Oil Viscosity Chart30
  - Engine Oil Viscosity Grade – Ambient Temperature30
- Recommended Lubricants30
- Engine Repair Kit31
Section 3. Engine Assembly (1)32
Engine Assembly (1)32
Disassembly34
- Fuel Injection Pipe with Clip35
- Injection Pump35
- Exhaust Manifold35
- Injection Nozzle Holder38
- Rocker Arm Shaft and Rocker Arm38
- Cylinder Head38
- Crankshaft Damper Pulley with Dust Seal39
- Idler Gear39
- Timing Gear Backlash Measurement39
- Idler Gear “A” End Play Measurement39
- Piston and Connecting Rod with Upper Bearing40
- Connecting Rod Cap with Lower Bearing40
- Camshaft with Camshaft Timing Gear and Thrust Plate40
- Flywheel40
- Crankshaft Bearing Cap with Lower Bearing41
- Crankshaft Upper Bearing41
- Tappet41
- Crankshaft Rear Oil Seal41
- Single Unit42
- Rocker Arm Shaft Bracket43
- Rocker Arm Shaft Snap Ring43
- Split Collar45
- Intake and Exhaust Valve45
- Piston and Connecting Rod46
- Connecting Rod Bearing47
- Piston Ring47
- Piston Pin Snap Ring47
- Piston Pin47
- Camshaft, Camshaft Timing Gear, and Thrust Plate48
- Camshaft Timing Gear49
- Thrust Plate49
Engine Assembly (2)50
- Cylinder Head Lower Face Warpage51
- Exhaust Manifold Fitting Face Warpage51
- Cylinder Head Height (Reference)51
Inspection and Repair51
- Valve Guide52
- Manifold Fitting Face Warpage52
- Valve Stem and Valve Guide Clearance52
- Valve Guide Replacement52
- Valve and Valve Seat Insert53
- Valve Guide Installation53
- Valve Stem Outside Diameter53
- Valve Thickness53
- Valve Seat Insert Removal54
- Valve Seat Insert Replacement54
- Valve Depression54
- Valve Contact Width54
- Valve Seat Insert Installation55
- Valve Seat Insert Correction55
- Valve Spring56
- Valve Spring Free Height56
- Valve Spring Inclination56
- Valve Spring Tension56
- Rocker Arm Shaft and Rocker Arm Clearance57
- Rocker Arm Shaft Run-Out57
- Rocker Arm Shaft Outside Diameter57
- Rocker Arm Correction58
- Cylinder Body58
- Cylinder Body Upper Face Warpage58
- Cylinder Liner Bore Measurement59
- Cylinder Liner Projection Inspection59
- Cylinder Body Bore Measurement60
- Cylinder Liner Removal60
- Cylinder Liner Grade Selection60
- Cylinder Liner Replacement60
- Cylinder Liner Installation61
- Piston Selection62
- Piston Grade Selection63
- Piston Grade63
- Cylinder Liner and Piston Clearance63
- Tappet and Push Rod64
- Tappet Outside Diameter64
- Push Rod Curvature65
- Tappet and Cylinder Body Clearance65
- Camshaft65
- Camshaft Journal Diameter65
- Camshaft and Camshaft Bearing66
- Camshaft Bearing Replacement66
- Camshaft Run-Out66
- Cam Height66
- Camshaft Bearing Installation67
- Camshaft End Play67
- Thrust Plate Replacement67
- Thrust Plate Removal67
- Crankshaft and Bearing68
- Crankshaft Tufftriding Inspection68
- Judgment68
- Crankshaft Journal and Crankpin Diameter69
- Crankshaft Run-Out69
- Bearing Tension69
- Crankshaft Journal and Bearing Clearance70
- Connecting Rod Bearing Inside Diameter70
- Crankpin and Bearing Clearance71
- Crankshaft Timing Gear Replacement73
- Crankshaft Timing Gear Removal73
- Crankshaft Timing Gear Installation73
- Crankshaft Pilot Bearing Installation74
- Crankshaft Pilot Bearing Replacement74
- Crankshaft Pilot Bearing74
- Flywheel and Ring Gear75
- Ring Gear75
- Ring Gear Installation76
- Piston76
- Piston Ring Gap76
- Piston Ring and Piston Ring Groove Clearance77
- Piston Ring and Piston Ring Groove77
- Piston Pin Diameter78
- Piston Pin and Piston Clearance78
- Connecting Rod Bushing Removal78
- Connecting Rod Bushing Installation79
- Connecting Rod Alignment79
- Idler Gear Shaft and Idler Gear80
- Connecting Rod Side Face Clearance80
- Idler Gear Shaft Outside Diameter80
- Crankshaft Front Oil Seal Replacement81
- Idler Gear “A” Inside Diameter81
- Timing Gear Case Cover81
- Oil Seal Installation82
Engine Assembly (3)84
Reassembly85
- Rocker Arm Shaft86
- Valve Stem Oil Seal88
- Crankcase100
- Oil Pump with Oil Pipe101
- Flywheel Housing101
- Flywheel Housing Bolt Torque101
- Oil Pan102
- Intake Manifold108
Lubricating System112
- Item113
- Main Data and Specifications113
- General Description114
- Lubricating Oil Flow114
- Oil Pump117
- Vane and Pump Body Clearance118
- Oil Filter with Built-In Oil Cooler120
- Rotor and Vane Clearance118
- Vane, Rotor, and Cover Clearance118
- Relief Valve121
- Oil Cooler121
- Relief Vale123
Cooling System124
- Item125
- Main Data and Specifications125
- Coolant Flow126
- General Description126
- Water Pump127
- Water Pump128
- Thermostat134
Fuel System136
- Item137
- Main Data and Specifications137
- General Description138
- Fuel Filter and Water Separator140
- Injection Nozzle141
- Injection Pump Data146
- Injection Volume Adjustment146
- Governor Adjustment147
- Injection Quantity147
- Full Adjustment147
- Speed Lever Angle148
- Section 9. Engine Electricals150
Engine Electricals150
- Starter Identification151
- Armature157
- Armature Short Circuit Test157
- Armature Winding Ground Test157
- Armature Winding Continuity Test157
- Commutator Run-Out Test158
- Commutator Outside Diameter Measurement158
- Commutator Outside Diameter158
- Segment Mica Depth Measurement158
- Field Winding Continuity Test159
- Brush and Brush Holder159
- Field Winding Ground Test159
- Yoke159
- Brush Spring Inspection160
- Brush Holder Insulation Test160
- Pinion Clutch160
- Pinion Inspection160
- Pinion163
- Dust Cover163
- Shift Lever163
- Torsion Spring163
- Through Bolt164
- Lead Wire164
- Inspection after Reassembly164
- When Pinion Gap Deviates from Specified Value164
- Alternator165
- Alternator Identification165
- Rectifier with Brush Holder169
- Rotor and Bearing169
- Front Cover169
- Pulley and Fan169
- Ball Bearing170
- Rotor Coil Continuity Test171
- Rotor Coil Ground Test171
- Stator Coil Continuity Test171
- Stator Coil Ground Test172
- Rectifier (Positive Diode) Continuity Test172
- Rectifier (Negative Diode) Continuity Test173
- Rectifier Assembly Replacement Procedure173
- Brush174
Section 10. Troubleshooting178
- Hard Starting180
- Unstable Idling184
- Unstable Idling186
- Insufficient Power187
- Excessive Fuel Consumption191
- Excessive Oil Consumption193
- Overheating194
- White Exhaust Smoke196
- Dark Exhaust Smoke197
- Oil Pressure Does Not Rise198
- Abnormal Engine Noise200
- Engine Knocking200
- Continuous Noise201
- Gas Leakage Noise201
- Slapping Noise202
Section 11. Special Tool List204
- Special Tool List205
- General Rules208
Section 12. Repair Standards208
- Millimeters to Inches222
- Inches to Millimeters222
Section 13. Conversion Table222
- Feet to Meters223
- Length223
  - Meters to Feet223
  - Miles to Kilometers223
- Area224
- Volume224
- Mass226
- Pressure227
- Torque228
- Temperature229
- Fahrenheit to Centigrade229
- Centigrade to Fahrenheit229

Brand	Isuzu
Model	A-4JA1
Category	Engine
Language	English

Isuzu A-4JA1 User Manual

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