Isuzu 3LD User Manual

Table of Contents
U L-Series Diesel
Foreword 1
I. Introduction
Application Notes 2
Maintenance Schedule 3
General Family Information 4
II. Engine Component Description
Injection Pumps, Timing 5-8
Valve Train 9
Camshaft 10
Crank, Block, Pistons, Rods 11-14
Head Gasket 15
Cylinder Head 16
Lubrication 17-18
Cooling 19
III. Engine Servicing Procedures
Spill Port Timing 20
Valve Adjustment 21
Injector Service 22-24
Injector Pop-Off Test 25
Injector Leak Test 26
Glow plug Inspection 26
Hot plug Replacement 27
IV. Engine Repair Specifications – 3L 28-31
V. Engine Repair Specifications – 4L 32-35
VI. Component Failure Analysis 36-40
VII. Appendix – Misc. Service Information
Nozzle Troubleshooting Guide 41
Nozzle Performance & Diagnosis 42
Nozzle Holder Tightening Specifications 43-44
Turbo Diagnosis 45
Exhaust Temperature 46
Crankcase Pressure 46
Inlet Manifold Pressure 46
Used Oil Analysis 47
VIII. Isuzu Technology – L-Series Direct Injection 48-49

Isuzu 3LD Specifications

General

Brand	Isuzu
Model	3LD
Category	Engine
Language	English

Summary

Engine Component Description

Pump Description

Explains the function, components, and operation of the fuel injection pump.

Pump Timing

Details how pump timing is adjusted using shims and its effect on injection.

Pump Injection Sequence

Illustrates the intake and beginning of injection phases of the pump.

Pump Injection Sequence (continued)

Details the pressure feeding and end of injection phases of the pump.

Valve Train

Describes the rocker arm assembly, shaft, and associated oiling system.

Camshaft Design

Explains the camshaft construction, lobes, and bearing support system.

Crankshaft

Details the forged steel crankshaft, journal hardening, and balancing features.

Piston Sizing

Discusses piston matching, clearances, and service replacement options.

Connecting Rod

Explains the forged steel I-beam connecting rod and its components.

Cylinder Head Gasket

Details the three-layer head gasket, sealing bead, and installation sequence.

Cylinder Head

Covers cylinder head construction, compression testing, and warpage specifications.

Lubrication

Lubrication (continued)

Cooling System

Engine Servicing Procedures

Spill Port Timing

Valve Adjustment

Injector Service

Injector Service (continued)

Injector Pop-off Test

Injector Leak Test

Glow Plug Inspection

Hot Plug Replacement

Engine Repair Specifications – 3L

Engine Repair Specifications – 4L

Maintenance Specifications

Mechanical Specifications

Torque Specifications

Lubrication and Sealant Specifications

Component Failure Analysis

Fuel System

Cylinder Block

Discusses potential failure modes related to the cylinder block.

Piston

Piston Failure