2004 ISUZU TF SERIES INJECTION

8A-12 ELECTRICAL-BODY AND CHASSIS
ABBREVIATIONS
Abbreviation Meaning of abbreviation Abbreviation Meaning of abbreviation
A Ampere (S) LH Left hand
ABS Anti-lock brake system LWB Long wheel base
ASM Assembly MPI Multipart fuel injection
AC Alternating current M/T Manual transmission
A/C Air conditioner QOS Quick On Start system
ACC Accessories RH Right hand
CARB Carburetor RR Rear
C/B Circuit breaker RWAL Rear wheel anti-lock brake system
CSD Cold start device SRS Supplemental restraint system
DIS Direct ignition system ST Start
EBCM Electronic brake control module STD Standard
ECGI Electronic control gasoline injection SW Switch
ECM Engine control module SWB Short wheel base
ECU Electronic control unit TCM Transmission control module
EFE Early fuel evaporation V Volt
42 Two-wheel drive VSV Vacuum switching valve
44 Four-wheel drive W Watt (S)
FL Fusible link WOT Wide open throttle
FRT Front W/ With
H/L Headlight W/O Without
IC Integrated circuit
IG Ignition
kW Kilowatt

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

TROUBLESHOOTING 6 – 7
4. Excessive Fuel Consumption
Step Action Value(s) Yes No
1 Was the air cleaner element clogged? — Clean or
replace the air
cleaner
element. Go to Step 2
2 Was the air leakage found from the air intake side of
the turbocharger? — Repair or
replace the air
intake side of
the
turbocharger. Go to Step 3
3 Was the turbocharger working completely? —
Go to Step 4 Replace the
turbocharger
4 Was there the fuel leakage? — Repair or
replace the fuel
leakage part. Go to Step 5
5 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at
200 rpm
Go to Step 6 Readjust the
valve clearance
or replace the
cylinder head
gasket or
cylinder liner or
piston or piston
ring or valve
and valve seat
6 Was the injection nozzle pressure or spray pattern
normal? —
Go to Step 7 Replace the
injection nozzle
7 Are any DTC stored? — Go to indicated
DTC Solved

6 – 10 TROUBLESHOOTING
8. Dark Exhaust Smoke
Step Action Value(s) Yes No
1 Was the air cleaner element normal condition? —
Go to Step 2 Clean or
replace the air
cleaner
element
2 Was the EGR valve sticking? — Replace the
EGR valve Go to Step 3
3 Was the injection nozzle pressure or the injection
spray pattern OK? —
Go to Step 4 Replace the
injection nozzle
4 Was the oil leakage found from the turbocharger oil
seal? — Replace the oil
seal Go to Step 5
5 Was the oil drain pipe of the turbocharger restricted?— Repair or
replace the oil
drain pipe Go to Step 6
6 Was restricted the oil drain passage in the
turbocharger center housing restricted? — Clean the
center housing Go to Step 7
7 Does turbine wheel has any impact damage? — Replace the
turbocharger Go to Step 8
8 Does PCV (Positive Crankcase Ventilation) Valve
has problem? — Repair or
replace the
relation parts Go to Step 9
9 Are any DTC stored? — Go to indicated
DTC Solved

6 – 12 TROUBLESHOOTING
10. Abnormal Engine Noise
10–1 Engine knocking
Step Action Value(s) Yes No
1 Was the injection nozzle pressure or injection spray
pattern OK? —
Go to Step 2 Replace the
injection nozzle
2 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at
200 rpm Go to Step 3 Replace the
cylinder head
gasket or
piston ring
3 Are any DTC stored? — Go to indicated
DTC Solved

10–2 Gas leakage noise
Step Action Value(s) Yes No
1 Was the exhaust pipe loose or broken? — Retighten or
replace the
exhaust pipe Go to Step 2
2 Was the exhaust manifold loose? — Retighten or
replace the
exhaust
manifold. Or
replace the
exhaust
manifold
gasket Go to Step 3
3 Was the injection nozzle loose? — Retighten or
replace the
injection nozzle
fixing bolt Go to Step 4
4 Was the cylinder head gasket broken? — Replace the
cylinder head
gasket Go to Step 5
5 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)