Isuzu 4LB1 Instruction manual

INDUSTRIAL DIESEL ENGINE 4LB1, 4LC1, 4LE1

ISUZU MOTORS LIMITED
A4-6-RANGE - Printed In England
ENGLISH - 9806/4000 - ISSUE 1- FEBRUARY 09
WORKSHOP MANUAL
INDUSTRIAL DIESEL ENGINE 4LB1, 4LC1, 4LE1

0 0
9806-4000
Notes:

INDUSTRIAL
DIESEL ENGINE
4LB1, 4LC1, 4LE1
MODELS
ISUZU MOTORS LIMITED
WORKSHOP MANUAL

FOREWORD
This Workshop Manual is designed to help you perform necessary
maintenance, service, and repair procedures on applicable Isuzu
industrial engines.
Information contained in this Workshop Manual is the latest
available at the time of publication.
Isuzu reserves the right to make changes at any time without prior
notice.

TABLE OF CONTENTS
SECTION 1. GENERAL INFORMATION.................................. 1
SECTION 2. ENGINE ....................................................... 27
SECTION 3. LUBRICATING SYSTEM .................................... 83
SECTION 4. COOLING SYSTEM ......................................... 87
SECTION 5. FUEL SYSTEM ............................................... 93
SECTION 6. TROUBLESHOOTING ....................................... 105
SECTION 7. SPECIAL TOOL .............................................. 111
SECTION 8. CONVERSION TABLE....................................... 113

GENERAL INFORMATION 1
SECTION 1
GENERAL INFORMATION
TABLE OF CONTENTS
CONTENTS PAGE
GENERAL REPAIR INSTRUCTIONS ....................................................................... 2
NOTES ON THE FORMAT OF THIS MANUAL ........................................................... 2
APPEARANCE ................................................................................................ 5
MAIN DATA AND SPECIFICATIONS....................................................................... 7
TIGHTENING TORQUE SPECIFICATIONS ................................................................ 9
ANGULAR NUT AND BOLT TIGHTENING METHOD.................................................... 11
TIGHTENING TORQUE ON MAJOR COMPONENTS ................................................... 13
GASKET LOCATION ......................................................................................... 19
MAINTENANCE .............................................................................................. 21
RECOMMENDED LUBRICATING OIL...................................................................... 26

2GENERAL INFORMATION
GENERAL REPAIR INSTRUCTIONS
1. Before performing any service operation with the engine mounted, disconnect the grounding cable
from the battery.
This will reduce the chance of cable damage and burning due to short circuiting.
2. Always use the proper tool or tools for the job at hand.
Where specified, use the specially designed tool or tools.
3. Use genuine ISUZU parts referring ISUZU PARTS CATALOG for the engines.
4. Never reuse cotter pins, gaskets, O-rings, lock washers, and self locking nuts. Discard them as you
remove them. Replace them with new ones.
5. Always keep disassembled parts neatly in groups. This will ensure a smooth reassembly operation.
It is especially important to keep fastening parts separate. These parts vary in hardness and design,
depending on their installation position.
6. All parts should be carefully cleaned before inspection or reassembly.
Oil ports and other openings should be cleaned with compressed air to make sure that they are com-
pletely free of obstructions.
7. Rotating and sliding part surfaces should be lubricated with oil or grease before reassembly.
8. If necessary, use a sealer on gaskets to prevent leakage.
9. Nut and bolt torque specifications should be carefully followed.
10. Always release the air pressure from any machine-mounted air tank(s) before dismounting the engine
or disconnecting pipes and hoses.
11. Always check and recheck your work. No service operation is complete until you have done this.
12. Information contained in the “Main Data and Specifications” of the Workshop Manual and the Instruc-
tion Book may differ. In this case, the information contained in the Instruction Book should be
considered applicable.
NOTES ON THE FORMAT OF THIS MANUAL
This Workshop Manual is applicable to the 3LA1, 3LB1, 3LD1 family of industrial diesel engines. Unless
otherwise specified, these engines have common parts and components as well as data and specifica-
tions.
Illustrations used in this Workshop Manual are based on the 3LB1 and 3LD1 engines.
1. Find the applicable section by referring to the Table of Contents at the beginning of the Manual.
2. Common technical data such as general maintenance items, service specifications, and tightening
torques are included in the “General Information” section.
3. Each section is divided into sub-sections dealing with disassembly, inspection and repair, and
reassembly.
4. When the same servicing operation is applicable to several different units, the manual will direct you
to the appropriate page.
5. For the sake of brevity, self-explanatory removal and installation procedures are omitted.
More complex procedures are covered in detail.

GENERAL INFORMATION 3
6. Each service operation section in this Workshop Manual begins with an exploded view of the applica-
ble area.
(Example)
Major components
Figures in parentheses “( )” show the order of disassembling or reassembling.
7. Measurement criteria are defined by the terms “standard” and “limit”.
A measurement falling within the “standard” range indicates that the applicable part or parts are ser-
viceable.
“Limit” should be thought of as an absolute value.
A measurement which is outside the “limit” indicates that the applicable part or parts must be either
repaired or replaced.
8. Components and parts are listed in the singular form throughout the Manual.
Water Outlet Pipe (5)
Packing (6)
Thermostat (7)
Water Pump ASM (8)
Pully; Fan (4)
Spacer (2)
Fan; Cooling (1)
Belt; Fan (3)
Fig. 1

4GENERAL INFORMATION
9. The following symbols appear throughout this Worshop Manual. They tell you the type of service
operation or step to perform.
. . . Remove . . . Adjustment
. . . Installation . . . Cleaning
. . . Disassembly . . . Important Operation Requiring Extra Care
. . . Reassembly . . . Specified Torque (Tighten)
. . . Alignment (Marks) . . .
. . . Directional Indication . . .
. . . Inspection . . . Lubrication (Oil)
. . . Measurement . . . Lubrication (Grease)
. . . Liquid Gasket Application
10. Direction used in this Manual are as follows:
Front
The cooling fan side of the engine viewed from the flywheel.
Right
The injection pump side of the engine.
Left
The exhaust manifold side of the engine.
Rear
The flywheel side of the engine.
Cylinder numbers are counted from the front of the engine.
The front most cylinder is No. 1 and rear most cylinder is No.
The engine’s direction of rotation is counterclockwise viewed from the flywheel.
Special Tool Use Required for Recommended
(Isuzu Tool or Tools)
Commercially Available Tool Use Required or
Recommended

GENERAL INFORMATION 5
APPEARANCE
1. MODELS 4LC1 AND 4LB1 AND 4LE1
(1) Left side view
(2) Right side view
Fig. 2
Fig. 3

6GENERAL INFORMATION
2. MODEL 4LB1T (with turbocharger)
(1) Left side view
(2) Right side view
Fig. 4
Fig. 5

GENERAL INFORMATION 7
MAIN DATA AND SPECIFICATIONS
1. MODELS 4LB1 AND 4LB1T
Item
Engine model(s) 4LB1 4LB1T
Type In-line water cooled 4-cycle type, OHV: diesel engine
Timing drive system Gear drive
Number of piston rings Compression rings 2, and oil ring 1
No. of cylinders - bore ×stroke mm 4 – 77.4 ×79.7
Displacement cc (cid) 1499 (92)
Compression ratio 22 : 1
Type of combustion chamber Swirl chamber
Overall length ×width ×height mm * 554 ×436 ×579 554 ×466 ×611
Dry weight kg (lb) * 130 (287) 137 (302)
Fuel injection timing (BTDC) (when at stop) * 16°
Firing order 1 – 3 – 4 – 2
Fuel Highspeed diesel fuel (SAE No.2)
Idling speed r.p.m * 850
Compression pressure kg/cm2(psi/MPa) 31 (441/3) or more/250 r.p.m.
Valve clearance (cold) Intake 0.4 (0.0157)
mm (in) Exhaust 0.4 (0.0157)
Intake valve
Open (BTDC) 15°
Valve Close (ABDC) 29°
operating
Exhaust valve
Open (BBDC) 40°
timing
Close (ATDC) 16°
Injection pump Bosch type
Governor Mechanical type
Nozzle Throttle type
Injection pressure kg/cm2(psi/MPa) * 135 (1920/13.2)
Oil pump Trochoid type
Oil filter Cartridge type
Lubricant capacity: In total lit (qts) * About 7.3 (7.7)
Generator output (V – A) * 12 – 20
Starter output (V – KW) * 12 – 1.0
(Note) These specifications may be subject to change without notice.
Figures in the column with an asterisk (*) are different for each machine. Refer to the specifica-
tions provided by machine manufacturers.

8GENERAL INFORMATION
2. MODELS 4LC1 AND 4LE1
Item
Engine model(s) 4LC1 4LE1
Type In-line water cooled 4-cycle type, OHV: diesel engine
Timing drive system Gear drive
Number of piston rings Compression rings 2, and oil ring 1
No. of cylinders - bore ×stroke mm 4 – 77.4 ×92 4 – 85 ×92
Displacement cc (cid) 1731 (106) 2179 (133)
Compression ratio 22 : 1 21.5 : 1
Type of combustion chamber Swirl chamber
Overall length ×width ×height mm * 554 ×436 ×606 691 ×449 ×616
Dry weight kg (lb) * 143 (315) 155 (342)
Fuel injection timing (BTDC) (when at stop) * 16°
Firing order 1 – 3 – 4 – 2
Fuel Highspeed diesel fuel (SAE No.2)
Idling speed r.p.m * 850
Compression pressure kg/cm2(psi/MPa) 31 (441/3) or more/250 r.p.m.
Valve clearance (cold) Intake 0.4 (0.0157)
mm (in) Exhaust 0.4 (0.0157)
Intake valve
Open (BTDC) 15°
Valve Close (ABDC) 29°
operating
Exhaust valve
Open (BBDC) 40°
timing
Close (ATDC) 16°
Injection pump Bosch type
Governor Mechanical type
Nozzle Throttle type
Injection pressure kg/cm2(psi/MPa) * 135 (1920/13.2)
Oil pump Trochoid type
Oil filter Cartridge type
Lubricant capacity: In total lit (qts) * About 7.3 (7.7) About 8.7 (9.2)
Generator output (V – A) * 12 – 20
Starter output (V – KW) * 12 – 1.0
(Note) These specifications may be subject to change without notice.
Figures in the column with an asterisk (*) are different for each machine. Refer to the specifica-
tions provided by machine manufacturers.

GENERAL INFORMATION 9
TIGHTENING TORQUE SPECIFICATIONS
The tightening torque values given in the table below are applicable to the bolts unless otherwise
specified.
STANDARD BOLT kg·m (lb.ft/N·m)
An asterisk (*) indicates that the bolts are used for female threaded parts that are made of soft materials
such as casting. Those shown in parentheses in the strength class indicate the classification by the old
standard.
M 6 × 1.0
M 8 × 1.25
M10 × 1.25
M12 × 1.25
M14 × 1.5
M16 × 1.5
M18 × 1.5
M20 × 1.5
M22 × 1.5
M24 × 2.0
*M10 × 1.5
*M12 × 1.5
*M14 × 2.0
*M16 × 2.0
0.4〜0.8
(2.9〜5.8/3.9〜7.8)
0.8〜1.8
(5.8〜13.0/7.8〜17.7)
2.1〜3.5
(15.2〜25.3/20.6〜34.3)
5.0〜7.5
(36.2〜54.2/49.0〜73.6)
7.8〜11.7
(56.4〜84.6/78.5〜114.7)
10.6〜16.0
(76.7〜115.7/103.0〜156.9)
15.4〜23.0
(111.1〜166.4/151.0〜225.6)
21.0〜31.6
(151.9〜228.6/205.9〜307.9)
25.6〜42.2
(185.2〜305.2/251.1〜413.8)
36.6〜55.0
(264.7〜397.8/358.9〜539.4)
2.0〜3.4
(14.5〜24.6/19.6〜32.4)
4.6〜7.0
(33.3〜50.6/45.1〜68.7)
7.3〜10.9
(52.8〜78.8/71.6〜106.9)
10.2〜15.2
(73.8〜110.0/100.0〜149.1)
0.5〜1.0
(3.6〜7.2/4.9〜9.8)
1.2〜2.3
(8.7〜16.6/11.8〜22.6)
2.8〜4.7
(20.3〜34.0/27.5〜46.1)
6.2〜9.3
(44.8〜67.3/60.8〜91.2)
9.5〜14.2
(68.7〜102.7/93.2〜139.3)
13.8〜20.8
(99.8〜150.4/135.3〜204.0)
19.9〜29.9
(143.9〜216.3/195.2〜391.3)
27.5〜41.3
(198.9〜298.7/269.7〜405.0)
37.0〜55.5
(267.6〜401.4/362.9〜544.3)
43.9〜72.5
(317.5〜523.9/430.5〜711.0)
2.8〜4.6
(20.3〜33.3/27.5〜45.1)
5.8〜8.6
(42.0〜62.2/56.9〜84.3)
9.0〜13.4
(65.1〜96.9/88.3〜131.4)
13.2〜19.8
(95.5〜143.2/129.5〜194.2)
1.7〜3.1
(12.3〜22.4/16.7〜30.4)
3.8〜6.4
(27.5〜46.3/37.3〜62.8)
7.7〜11.6
(55.7〜83.9/75.5〜113.8)
11.6〜17.4
(83.9〜125.6/113.8〜170.6)
16.3〜24.5
(118.9〜177.2/159.9〜240.3)
23.4〜35.2
(169.3〜254.6/229.5〜345.2)
32.3〜48.5
(233.6〜350.8/316.8〜475.6)
43.3〜64.9
(313.2〜469.4/424.6〜636.5)
56.5〜84.7
(408.7〜612.6/554.1〜830.6)
3.7〜6.1
(26.8〜44.1/36.3〜59.8)
7.3〜10.9
(52.8〜78.8/71.6〜106.9)
10.9〜16.3
(78.8〜118.9/106.9〜159.9)
15.6〜23.4
(112.8〜169.3/162.8〜229.5)
Refined
No mark
Non-Refined
4.8 (4T) 8.8(7T) 9.8 (9T)
Strength
Class
Bolt
Identification
Bolt
Diameter ×
pitch (mm)

10 GENERAL INFORMATION
TIGHTENING TORQUE SPECIFICATIONS
The tightening torque values given in the table below are applicable to the bolts unless otherwise
specified.
FLANGED HEAD BOLT kg·m (lb.ft/N·m)
M 6 ×10.5〜0.9 0.6〜1.2
(3.61〜6.50/4.6〜8.5) (4.33〜8.67/5.88〜11.76)
M 8 ×1.25 1.1〜2.0 1.4〜2.9 1.9〜3.4
(7.95〜14.46/10.78〜19.61) (4.33〜8.67/5.88〜11.76) (13.74〜24.59/18.63〜33.34)
M10 ×1.25 2.3〜3.9 3.6〜6.4 4.3〜7.2
(17.35〜28.20/23.53〜38.24) (26.03〜44.12/35.30〜59.82) (31.10〜52.07/42.16〜70.60)
*M10 ×1.5 2.3〜3.8 3.5〜5.8 4.1〜6.8
(16.63〜27.48/22.55〜37.26) (25.31〜41.95/34.32〜56.87) (29.65〜49.18/40.20〜66.68)
M12 ×1.25 5.6〜8.4 7.9〜11.9 8.7〜13.0
(40.50〜60.75/54.91〜82.37) (57.14〜86.07/77.47〜116.69) (62.92〜94.02/85.31〜127.48)
*M12 ×1.75 3.5〜9.5 7.3〜10.9 8.1〜12.2
(37.61〜56.41/50.99〜76.49) (52.80〜78.83/71.58〜106.89) (58.58〜88.24/79.43〜119.64)
M14 ×1.5 8.5〜12.7 11.7〜17.6 12.6〜18.9
(61.48〜91.85/83.35〜124.54) (84.62〜127.30/114.73〜172.59) (91.13〜136.70/123.56〜185.34)
*M14 ×27.6〜11.5 11.1〜16.6 11.8〜17.7
(57.14〜85.34/77.47〜115.71) (80.28〜120.06/108.85〜162.79) (85.34〜128.02/115.71〜173.57)
M16 ×1.5 11.8〜17.7 17.1〜26.5 18.0〜27.1
(85.34〜128.02/115.71〜173.57) (125.85〜189.50/170.63〜256.93) (130.19〜196.01/176.52〜265.76)
*M16 ×211.2〜16.7 16.6〜24.9 17.2〜25.7
(81.00〜120.79/109.83〜163.77) (120.06〜180.10/162.79〜244.18) (124.40〜186.61/168.67〜253.01)
A bolt with an asterisk (*) is used for female screws of soft material such as cast iron.
Bolt head
marking
Nominal
size
(dia. x pitch)

GENERAL INFORMATION 11
1. Carefully wash the nuts and bolts to remove all oil
and grease.
2. Apply a coat of molybdenum disulfide grease to the
threads and setting faces of the nuts and bolts.
3. Tighten the nuts and bolts to the specified torque
(snug torque) with a torque wrench.
Snug torque
4. Draw a line [A-B] across the center of each bolt.
Center line
ANGULAR NUT AND BOLT TIGHTENING METHOD
Fig. 6
Fig. 7
Fig. 8

12 GENERAL INFORMATION
Line
ABC D
5. Draw another line [C-D] on the face of each of the
parts to be clamped. This line should be an exten-
sion of the line [A-B].
6. Draw another line [F-G] on the face of each of the
parts to be clamped. This line will be in the direc-
tion of the specified angle [Q] across the center [E]
of the nut or bolt.
Specified angle (Q)
Coinciding line
E
F
G
7. Use a socket wrench to tighten each nut or bolt to
the point where the line [A-B] is aligned with the line
[F-G].
A
B
CD
F
G
Tighten
Example: Specified Angle and Tightening Rotation
A 30° 1/12 of a turn
B 60° 1/6 of a turn
C 90° 1/4 of a turn
D 180° 1/2 of a turn
E 360° One full turn
ABCDE
Fig. 9
Fig. 10
Fig. 11
Fig. 12

GENERAL INFORMATION 13
TIGHTENING TORQUE ON MAJOR COMPONENTS
1. COOLING FAN AND WATER PUMP
kg·m (ft. lbs.)
1.9 - 2.9
(13.7 - 21.0)
1.9 - 2.9
(13.7 - 21.0)
1.2 - 1.8
(8.7 - 13.0)
1.2 - 1.8
(8.7 - 13.0)
To cylinder head
1.9 - 2.9
(13.7 - 21.0)
To cylinder block
1.9 - 2.9
(13.7 - 21.0)
1.9 - 2.9
(13.7 - 21.0)
3.5 - 4.7
(25.3 - 34.0)
Fig. 13

14 GENERAL INFORMATION
2. CYLINDER HEAD AND CYLINDER HEAD COVER
kg·m (ft. lbs.)
(Without turbocharger)
(With turbocharger)
0.8 - 1.2
(5.8 - 8.7)
0.2 - 0.4
(1.4 - 2.9)
0.8 - 1.2
(5.8 - 8.7)
0.8 - 1.2
(5.8 - 8.7)
0.8 - 1.2
(5.8 - 8.7)
(Apply engine oil.)
8.5 - 9.5
(61.5 - 68.7)
↓
60°- 90°
1.5 - 2.0
(10.8 - 14.5)
1.9 - 2.9
(13.7 - 21.0)
0.09 - 0.11
(0.6 - 0.8)
2.5 - 3.5
(18.0 - 25.3)
(Apply engine oil.) 1.9 - 2.9
(13.7 - 21.0)
(Apply locktite No. 262 to this part.)
(Apply salant.)
Fig. 14