8A-432 ELECTRICAL-BODY AND CHASSIS
No. Connector face No. Connector face
F-1
White
Fuel filter
F-2
White
Fuel pump & sensor
F-3
NOT USED
F-4
Gray
ABS sensor
F-5
Gray
Rear combination lamp-RH
F-6
Gray
Rear combination lamp-LH
F-7
Gray
License plate lamp
F-8
Black
Rear fog light – RH
F-9
Black
Rear fog light - LH
6 – 4 TROUBLESHOOTING
1-3 Engine turn over but does not start engine
Incase of the fuel not being delivered to the injection pump
Step Action Value(s) Yes No
1 Check clogged, damaged the fuel piping or the
connector loosen.
Was any problem found? —
Repair replace
problem parts. Go to Step 2
2 Was the over flow valve on the fuel filter closed? — Repair replace
the over flow
valve Go to Step 3
3 Was the fuel filter element clogged? — Replace the
fuel filter
element Go to Step 4
4 Was the fuel line air bled? — Go to Step 5 Bleed the air
5 Are any DTC stored? — Go to indicated
DTC Solved
Incase of the fuel is being delivered to the injection pump
Step Action Value(s) Yes No
1 Was the water contain in the fuel? — Replace the
fuel Go to Step 2
2 Was the fuel line air bled? — Go to Step 5 Bleed the air
3 Was the injection spray condition complete? —
Go to Step 4 Replace the
injection nozzle
4 Was the injection nozzle injection starting pressure
OK? (See below)
Go to Step 5 Replace the
injection nozzle
5 Was the injection nozzle sticking? — Replace the
injection nozzle Go to Step 6
6 Are any DTC stored? — Go to indicated
DTC Solved
Injection nozzle opening pressure
1st = 19.5 MPa (199 kg/cm2, 2828 psi)
TROUBLESHOOTING 6 – 5
2. Unstable Idling
Step Action Value(s) Yes No
1 Was the fuel line air bled completely? — Go to Step 3 Bleed the air
2 Was the fuel line leakage or blockage found? — Repair or
replace relation
parts. Go to Step 4
3 Was the water contained in the fuel? — Replace the
fuel Go to Step 5
4 Was the fuel filter element clogged? — Replace the
fuel filter
element Go to Step 6
5 Was the injection starting pressure or the injection
spray condition OK? (See below)
Go to Step 7 Replace the
injection nozzle
6 Was the injection nozzle sticking? See Step 6 Replace the
injection nozzle Go to Step 8
7 Check the throttle valve condition.
Was the idling port clogged in the throttle valve? — Repair or
replace the
throttle valve Go to Step 9
8 Was the valve clearance improper adjusted? 0.4 mm
(0.016 in)
both intake
and exhaust
valves Adjust the
valve clearance Go to Step 10
9 Was the compression pressure OK? 3,040 kPa
(31 kg/cm2,
441 psi) at
200rpm
Go to Step 11 Readjust the
valve clearance
or replace the
cylinder head
gasket or
cylinder liner or
piston or piston
ring or valve
and valve seat
10 Are any DTC stored? — Go to indicated
DTC Solved
Injection nozzle opening pressure
1st = 19.5 MPa (199 kg/cm2, 2828 psi)
6 – 6 TROUBLESHOOTING
3. Insufficient Power
Step Action Value(s) Yes No
1 Was the air cleaner element condition OK? (Clogged
or not) —
Go to Step 2 Clean or
replace the air
cleaner
element.
2 Was the intake air leakage found from intake
system? — Repair or
replace the
intake air
system. Go to Step 3
3 Was the fuel filter element condition OK? (Clogged
or not) —
Go to Step 4 Clean or
replace the fuel
filter element.
4 Check the fuel injection pipes.
Does the injection pipes have obstruction or any
damage? — Repair or
replace the fuel
injection pipes. Go to Step 5
5 Was the water contained in the fuel? — Replace the
fuel Go to Step 6
6 Was the injection nozzle pressure or spray pattern
normal? —
Go to Step 7 Readjust the
injection nozzle
pressure or
replace the
nozzle.
7 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at
200 rpm
Go to Step 8 Readjust the
valve clearance
or replace the
cylinder head
gasket or
cylinder liner or
piston or piston
ring or valve
and valve seat
8 Was the exhaust pipe clogged? — Repair or
replace the
exhaust pipe. Go to Step 9
9 Was the exhaust gas leakage found from exhaust
system? — Repair or
replace the
exhaust
system. Go to Step 10
10 Was the waste gate control actuator hose broken or
cracked? — Replace the
hose. Go to Step 11
11 Was the waste gate working completely? —
Go to Step 12 Replace the
turbocharger
assembly.
12 Was turbocharger working completely? —
Go to Step 13 Replace the
turbocharger
assembly.
13 Are any DTC stored? — Go to indicated
DTC Solved
6A – 4 ENGINE MECHANICAL
MAIN DATA AND SPECIFICATIONS
Engine model
Item 4JA1T (L) 4JA1TC
Engine type
Combustion chamber type
Cylinder liner type
Timing gear train system Four-cycle, overhead valve, water cooled
Direct injection
Dry type, chrome plated
Gear drive
No. of cylinders-bore stroke mm (in) 4 – 93 92 (3.66 3.62)
No. of piston rings Compression ring: 2 / Oil ring: 1
Total piston displacement cm3 (in3)
Compression ratio (to 1) 2,499(152.4)
18.5
Compression pressure Mpa(kg/cm2/psi) 3.0 (31.0/441) – 200 rpm
Engine weight (dry) kg (lb) Approximately 239 (527)
Fuel injection order 1 – 3 – 4 - 2
Fuel injection timing BTDC deg 8 -
Specified fuel type
Idling speed rpm
Valve clearances (At cold): Intake mm (in)
Exhaust mm (in)
Intake valves Open at (BTDC) deg
Close at (ABDC) deg
Exhaust valves Open at (BBDC) deg
Close at (ATDC) deg
Fuel system JIS No. 2, DIN/EN590, GB252-1944 Diesel fuel
730 25 (A/C Off)
850 25 (A/C ON)
0.4 (0.016)
0.4 (0.016)
24.5
55.5
54.0
26.0
Injection pump type BOSCH distributor VE type BOSCH distributor VP44 type
Governor type Mechanical (Half all speed
type) Electronically controled
Injection nozzle type
Injection nozzle opening pressure Hole with 5 orifices
Mpa(kg/cm2/psi) 1st 19.1 (195 / 2,773) 1st 19.0 (194 / 2,755)
2nd (Reference)
25.527.0
(260275 / 3,7023,920) 2nd (Reference)
34.035.5
(347362 / 4,9365,154)
Main fuel filter type
Lubricating system
Lubricating method Cartridge paper element and water separator
Pressure circulation
Specified engine oil (API grade) ISUZU genuine 10W – 30 (API CD of ACEA B2/B3)
6A – 6 ENGINE MECHANICAL
MAIN DATA AND SPECIFICATIONS
Engine model
Item 4JH1TC
Engine type Four-cycle, overhead valve, water cooled
Combustion chamber type Direct injection
Cylinder liner type
Timing gear train system Dry type, chrome plated
Gear drive
No. of cylinders-bore stroke mm (in) 4 – 95.4 104.9 (3.76 4.13)
No. of piston rings Compression ring: 2 / Oil ring: 1
Total piston displacement liter
Compression ratio (to 1) 2,999
18.3
Compression pressure MPa(kg/cm2/psi) 3.0 (31.0/441) – 200 rpm
Engine weight (dry) kg (lb) MT : Approximately 249 (549)
AT : Approximately 236 (520)
Fuel injection order 1 – 3 – 4 - 2
Specified fuel type JIS No.2, DIN/EN590, GB252-1944 Diesel fuel
Idling speed rpm
700 25 (A/C OFF)
800 25 (A/C ON)
Valve clearances (At cold): Intake mm (in)
Exhaust mm (in)
Intake valves Open at (BTDC) deg
Close at (ABDC) deg
Exhaust valves Open at (BBDC) deg
Close at (ATDC) deg
Fuel system
Injection pump type 0.4 (0.016)
0.4 (0.016)
24.5
55.5
54.0
26.0
BOSCH distributor VP44 type
Injection nozzle type
Injection nozzle opening pressure
MPa(kg/cm
2/psi)Hole with 5 orifices
1st 19.5 (199/2,828)
2nd (Reference) 34.335.8 (350365/4,9805,197)
Main fuel filter type
Lubricating system
Lubricating method Cartridge paper element and water separator
Pressure circulation
Specified engine oil (API grade) ISUZU genuine 10W – 30 (API CD of ACEA B2/B3)
Oil pump type
Oil filter type Gear
Cartridge paper element
Oil capacity lit (US/UK gal)
6.2 (1.64/1.36) (For 4 2)
7.0 (1.85/1.54) (For 4 4)
Oil cooler type Water cooled
ENGINE MECHANICAL 6A – 25
Replenished Engine Oil MAX lit (US/UK gal)
Condition
Model Engine Dry
With oil filter
replacement Without oil
filter
replacement
4 2
4 4
(4JA1L/TC)6.2 (1.64/1.36) 5.2 4.2
(1.37 1.11
/ 1.14 0.92) 4.5 3.5
(1.19 0.93
/ 0.99 0.77)
4 2
(4JH1TC)
6.2 (1.64/1.36) 5.2 4.2
(1.37 1.11
/ 1.14 0.92) 4.5 3.5
(1.19 0.93
/ 0.99 0.77)
4 4
(4JH1TC) 7.0 (1.85/1.54) 6.2 5.2
(1.64 1.37
/ 1.36 1.14) 5.3 4.3
(1.72 1.14
/ 1.17 0.95)
9. Start the engine and check for oil leakage from the
main oil filter.
6A-7
FUEL SYSTEM
Fuel Filter Replacement Procedure
1. Remove the fuel filter by turning it counterclockwise
with a filter wrench.
Filter Wrench: 5-8840-0253-0 (J-22700)
Note:
Be careful not to spill the fuel in the filter cartridge.
RTW46ASH000501
2. Clean the fuel filter cartridge fitting faces.
This will allow the new fuel filter to seat properly
3. Apply a light coat of engine oil to the O-ring.
4. Turn in the fuel filter until the sealing face comes in
contact with the O-ring.
5. Turn in the fuel filter an additional 2/3 of a turn with a
filter wrench.
Filter Wrench : 5-8840-0253-0 (J-22700)
6. Operate the priming pump until the air discharged
completely from fuel system.
7. Start the engine and check for fuel leakage.
Note:
The use of an ISUZU genuine fuel filter is strongly
recommended.
041RY00009
6A – 26 ENGINE MECHANICAL
041RY00011
Draining Procedure
The indicator light will come on when the water level in the
water separator exceeds the specified level.
Drain the water and foreign material from the water
separator (inside chassis frame) with the following
procedure.
1. Place the drain pan under the drain plug.
2. Loosen the drain plug and drain water.
3. After draining the water, tighten the drain plug.
4. Operate the priming pump on the fuel filter several
times and check for fuel leakage.
5. Check the water separator indicator light. It should be
off.
Except EURO III model
RTW46ASH002901
For EURO III model
RTW46ASH000501
Air Bleeding
1. Operate the priming pump until strong resistance is
felt.
2. Wait 1 minute, and operate the priming pump until
strong resistance is felt.
3. Once more wait, and operate the priming pump until
strong resistance is felt.
4. Turn the ignition switch to the "ON" position. Wait until
the glow indicator lamp turns off.
5. Turn the ignition switch to the "START" position and
crank the engine until it starts.
6. If the engine does not start, repeat Step 3 - 5.
7. Allow the engine to idle for 3 minutes to bleed air
completely form the fuel system and check for fuel
leakage.
Note:
Insufficient air bleeding may cause the Diagnostic
Trouble Code (DTC) store or improper engine
performance.