2004 ISUZU TF SERIES fuel cap

6C – 18 FUEL SYSTEM
FUEL FILLER CAP




RTW36CSH000401
Legend

(1)
Pressure Valve

(2)
Vacuum Valve

(3)
Seal Ring


General Description
A vacuum valve and pressure valve are built into the fuel filler
cap which adjusts the fuel pressure in the fuel tank to prevent
fuel tank damage.


Inspection
The fuel filler cap must be inspected for seal condition.
The fuel filler cap must be replaced if found defective

CAUTION: A replacement fuel filler cap must be the same
as the original. The fuel filler cap valve was designed
primarily for this application and must be replaced with
the same type or decreased engine performance may
occur.

6C – 20 FUEL SYSTEM

7. Power Steering Pump Bracket


6C-4 8. Throttle Position Sensor Harness Connector
(4JA1TC/4JH1TC only)
Disconnect the harness connector from the throttle
position sensor.

9. Oil Level Gauge
10. Fuel Pipe
1) Disconnect the fuel hoses from the fuel filter or priming
pump.
2) Disconnect the fuel hoses from the injection pump.

11. Fuel Filter Assembly (Except EURO III model)
6C-5
12. Fuel Filter Bracket (Except EURO III model)
13. Leak Off Hose
Disconnect the leak off hose at the injection pump.
14. Injection Pipe Clip
15. Injection Pipe
1) Loosen the injection pipe sleeve nuts at the delivery
valve side and the injection nozzle side.
Note:
Do not apply excessive force to the injection pipes.
2) Loosen the injection pipe clip.
3) Remove the injection pipes.
Note:
Plug the delivery holder ports with the caps to prevent
the entry of foreign material.

16. Intake Manifold
1) Remove the EGR valve from the intake manifold and
EGR pipe.
2) Loosen the intake rubber hoses clip.
3) Loosen the intake manifold bolts and nuts.
17. Injection Pump Cover (4JA1TC/4JH1TC only)

6E–82 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
GENERAL SERVICE INFORMATION
Serviceability Issues
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold
sensor or switch is installed, it makes a wrong diagnosis
and turns on the check engine lamp.
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the check
engine lamp.
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the check
engine lamp to turn on if the vehicle is not maintained
properly. Restricted oil filters, fuel filters, and crankcase
deposits due to lack of oil changes or improper oil
viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a “non-vehicle
fault”, but with the sensitivity of OBD diagnostics,
vehicle maintenance schedules must be more closely
followed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any
diagnostic procedure or diagnosing the cause of an
emission test failure. This can often lead to repairing a
problem without further steps. Use the following
guidelines when performing a visual/physical
inspection:
Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.
Inspect hoses that are difficult to see behind other
components.
Inspect all wires in the engine compartment for
proper connections, burned or chafed spots, pinched
wires, contact with sharp edges or contact with hot
exhaust manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain
when performing diagnostic procedures could result in
an incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to
effectively use this section of the Service Manual.
ON-BOARD DIAGNOSTIC (OBD)
On-Board Diagnostic (Self Diagnosis
System) Tests
A diagnostic test is a series of steps, the result of which
is a pass or fail reported to the diagnostic ex ecutive.
When a diagnostic test reports a pass result, the
diagnostic ex ecutive records the following data:
The diagnostic test has been completed since the
last ignition cycle.
The diagnostic test has passed during the current
ignition cycle.
The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the
diagnostic ex ecutive records the following data:
The diagnostic test has been completed since the
last ignition cycle.
The fault identified by the diagnostic test is currently
active.
The fault has been active during this ignition cycle.
The operating conditions at the time of the failure.
The Diagnostic Executive
The Diagnostic Executive is a unique segment of
software which is designed to coordinate and prioritize
the diagnostic procedures as well as define the protocol
for recording and displaying their results. The main
responsibilities of the Diagnostic Ex ecutive are listed as
follow s:
Commanding the check engine lamp on and off
DTC logging and clearing
Current status information on each diagnostic
Diagnostic Information
The diagnostic charts and functional checks are
designed to locate a faulty circuit or component through
a process of logical decisions. The charts are prepared
with the requirement that the vehicle functioned
correctly at the time of assembly and that there are not
multiple faults present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complemented
by the diagnostic procedures contained in this manual.
The language of communicating the source of the
malfunction is a system of diagnostic trouble codes.
When a malfunction is detected by the control module, a
diagnostic trouble code is set and the check engine
lamp is illuminated.
Check Engine Lamp
The check engine lamp looks the same as the check
engine lamp you are already familiar with, the “Check
Engine” lamp.
Basically, the check engine lamp is turned on when the

6E–368 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
15 Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions.
Objects blocking at the gauze filter. Check for a
condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
ex tended maintenance interval.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
fuel.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
eye bolt with
gauze filter and
verify repair Go to Step 16
16 Remove the injection nozzles from the engine and
check for the following conditions.
Improper splay condition.
Operating pressure is incorrect.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
injection nozzle
and verify repair Go to Step 17
17 Check the engine compression pressure for each
cylinders.
If a problem is found, repair as necessary.
Was the problem found?
More than 2.1
Mpa Verify repair Go to Step 18 Step Action Value(s) Yes No
1st Stage 2nd Sta ge
4JA1-TCApproximatly
19.0 MpaApprox ima tly
33.5 Mpa
4JH1-TCApproximatly
19.5 MpaApprox ima tly
33.8 Mpa

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–375
30 Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions.
Objects blocking at the gauze filter. Check for a
condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
ex tended maintenance interval.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
fuel.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
eye bolt with
gauze filter and
verify repair Go to Step 32
31 Remove the injection nozzles from the engine and
check for the following conditions.
Improper splay condition.
Operating pressure is incorrect.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
injection nozzle
and verify repair Go to Step 32
32 Check the engine compression pressure for each
cylinders. Each cylinder must be evenly.
If a problem is found, repair as necessary.
Was the problem found?
More than 2.1
Mpa Verify repair Go to Step 33 Step Action Value(s) Yes No
1st Stage 2nd Sta ge
4JA1-TCApproximatly
19.0 MpaApprox ima tly
33.5 Mpa
4JH1-TCApproximatly
19.5 MpaApprox ima tly
33.8 Mpa

6E–410 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
25 Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions.
Objects blocking at the gauze filter. Check for a
condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
ex tended maintenance interval.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
fuel.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
eye bolt with
gauze filter and
verify repair Go to Step 26
26 Remove the injection nozzles from the engine and
check for the following conditions.
Improper splay condition.
Operating pressure is incorrect.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
injection nozzle
and verify repair Go to Step 27 Step Action Value(s) Yes No
1st Stage 2nd Sta ge
4JA1-TCApproximatly
19.0 MpaApprox ima tly
33.5 Mpa
4JH1-TCApproximatly
19.5 MpaApprox ima tly
33.8 Mpa

ENGINE MECHANICAL (6VE1 3.5L) 6A-3
General Description
Engine Cleanliness And Care
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the thousandths of a
millimeter (ten thousandths of an inch). Accordingly,
when any internal engine parts are serviced, care and
cleanliness are important. Throughout this section, i
t
should be understood that proper cleaning and
protection of machined surfaces and friction areas is
part of the repair procedure. This is considered
standard shop practice even if not specifically stated.


A liberal coating of engine oil should be applied to
all friction areas during assembly to protect and
lubricate the surfaces on initial operation.

Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and
crankshaft journal bearings are removed fo
r
service, they should be retained in order.


At the time of installation, they should be installed
in the same locations and with the same mating
surfaces as when removed.

Battery cables should be disconnected before any
major work is performed on the engine. Failure to
disconnect cables may result in damage to wire
harness or other electrical parts.

The six cylinders of this engine are identified by
numbers; Right side cylinders 1, 3 and 5, Left side
cylinders 2, 4 and 6, as counted from crankshaf
t
pulley side to flywheel side.
General Information on Engine Service
The following information on engine service should be
noted carefully, as it is important in preventing damage
and contributing to reliable engine performance.

When raising or supporting the engine for any
reason, do not use a jack under the oil pan. Due to
the small clearance between the oil pan and the oil
pump strainer, jacking against the oil pan may
cause damage to the oil pick-up unit.

The 12-volt electrical system is capable o
f
damaging circuits. When performing any work
where electrical terminals could possibly be
grounded, the ground cable of the battery should
be disconnected at the battery.


Any time the intake air duct or air cleaner is
removed, the intake opening should be covered.
This will protect against accidental entrance o
f
foreign material into the cylinder which could
cause extensive damage when the engine is
started.
Cylinder Block
The cylinder block is made of aluminum die-cast casting
for 75Vtype six cylinders. It has a rear plate integrated
structure and employs a deep skirt. The cylinder liner is
cast and the liner inner diameter and crankshaft journal
diameter are classified into grades. The crankshaft is
supported by four bearings of which width is differen
t
between No.2, No.3 and No.1, No.4; the width of No.3
bearing on the body side is different in order to suppor
t
the thrust bearing. The bearing cap is made of nodular
cast iron and each bearing cap uses four bolts and two
side bolts.
Cylinder Head
The cylinder head, made of aluminum alloy casting
employs a pent-roof type combustion chamber with a
spark plug in the center. The intake and exhaust valves
are placed in V-type design. The ports are cross-flo
w
type.
Valve Train
Intake and exhaust camshaft on the both side of banks
are driven through an camshaft drive gear by timing
belt. The valves are operated by the camshaft and the
valve clearance is adjusted to select suitable thickness
shim.
Intake Manifold
The intake manifold system is composed of the
aluminum cast common chamber and intake manifold
attached with six fuel injectors.
Exhaust Manifold
The exhaust manifold is made of nodular cast iron.
Pistons and Connecting Rods
Aluminum pistons are used after selecting the grade
that meets the cylinder bore diameter. Each piston has
two compression rings and one oil ring. The piston pin
made of chromium steel is offset 1mm toward the thrus
t
side, and the thrust pressure of piston to the cylinder
wall varies gradually as the piston travels. The
connecting rods are made of forged steel. The
connecting rod bearings are graded for correct size
selection.
Crankshaft and Bearings
The crankshaft is made of Ductile cast-iron. Pins and
journals are graded for correct size selection for thei
r
bearing.
Engine Control Module (ECM)
The ECM location is on the common charmber.

6A-24 ENGINE MECHANICAL (6VE1 3.5L)
Common Chamber
Removal
1. Disconnect battery ground cable.
2. Remove air cleaner duct assembly.
3. Remove the ECM.

Disconnect the two connectors from the ECM.

Remove fixing bolts on the common chamber.

Remove fixing bolts for ground cable.




060RW025
4. Remove the accelerator control cable from
accelerator control cable bracket.

Slide the lock in direction A

Rotate the ratchet ring in indirection an arro
w
90




RTW46ASH000201
Legend
(1) Cable Bracket
(2) Ratchet ring
(3) Outer Cap
(4) Lock
(5) Paint Mark
(6) Arrow Mark

5. Remove the accelerator control cable from the
throttle.
6. Disconnect vacuum booster hose from common
chamber.
7. Disconnect connector from manifold absolute
pressure sensor, idle air control valve, throttle
position sensor, solenoid valve, electric vacuum
sensing valve.
8. Disconnect vacuum hose on canister VSV and
positive crankcase ventilation hose, fuel rail
assembly with pressure control valve bracket.
9. Remove ventilation hose from throttle valve and
intake duct and remove water hose.
10. Remove exhaust gas recirculation valve assembly
fixing bolt and nut on common chamber.
11. Remove two bolts from common chamber rea
r
side for remove fuel hose bracket.
12. Remove common chamber four bolts and fou
r
nuts then remove the common chamber.



025RW001
Legend
(1) Common Chamber
(2) Throttle Valve Assembly
(3) Bolt

13. Remove the four throttle body fixing bolts.