2004 ISUZU TF SERIES width

6E–98 ENGINE DRIVEABILITY AND EMISSIONS
FUEL METERING SYSTEM CHECK
Some failures of the fuel metering system will result in
an “Engine Cranks But Will Not Run” symptom. If this
condition ex ists, refer to the Cranks But Will Not Run
chart. This chart will determine if the problem is caused
by the ignition system, the ECM, or the fuel pump
electrical circuit.
Refer to Fuel System Electrical Test for the fuel system
wiring schematic.
If there is a fuel delivery problem, refer to Fuel System
Diagnosis, which diagnoses the fuel injectors, the fuel
pressure regulator, and the fuel pump.
Followings are applicable to the vehicles with
closed Loop System:
If a malfunction occurs in the fuel metering system, it
usually results in either a rich HO2S signal or a lean
HO2S signal. This condition is indicated by the HO2S
voltage, which causes the ECM to change the fuel
calculation (fuel injector pulse width) based on the
HO2S reading. Changes made to the fuel calculation
will be indicated by a change in the long term fuel trim
values which can be monitored with a Scan Tool. Ideal
long term fuel trim values are around 0%; for a lean
HO2S signal, the ECM will add fuel, resulting in a fuel
trim value above 0%. Some variations in fuel trim values
are normal because all engines are not ex actly the
same. If the evaporative emission canister purge is 02
status may be rich condition. 02 status indicates the
lean condition, refer to DTC P1171 for items which can
cause a lean HO2S signal.
FUEL INJECTOR COIL TEST PROCEDURE
AND FUEL INJECTOR BALANCE TEST
PROCEDURE
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Relieve the fuel pressure by connecting 5-8840-
0378-0 T-Joint to the fuel pressure connection on the
fuel rail.
Caution: In order to reduce the risk of fire and
personal injury, wrap a shop towel around the
fuel pressure connection. The towel will absorb
any fuel leakage that occurs during the
connection of the fuel pressure gauge. Place the
towel in an approved container when the
connection of the fuel pressure gauge is
complete.
Place the fuel pressure gauge bleed hose in an
approved gasoline container.
With the ignition switch OFF open the valve on the
fuel pressure gauge.
3. Record the lowest voltage displayed by the DVM
after the first second of the test. (During the first
second, voltage displayed by the DVM may be
inaccurate due to the initial current surge.)
Injector Specifications:
The voltage displayed by the DVM should be
within the specified range.
The voltage displayed by the DVM may increase
throughout the test as the fuel injector windings
warm and the resistance of the fuel injector
windings changes.Resistance OhmsVoltage Specification at
10°C-35°C (50°F-95°F)
11.8-12.6 5.7-6.6

ENGINE DRIVEABILITY AND EMISSIONS 6E–109
The fuel injector(s).
4. Fuel pressure that drops off during acceleration,
cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using a
Tech 2 Scan Tool.
Following are applicable to the vehicle with
closed Loop System:
If an ex tremely lean condition occurs, the ox ygen
sensor(s) will stop toggling. The ox ygen sensor
output voltage(s) will drop below 500 mV. Also, the
fuel injector pulse width will increase.
Important: Make sure the fuel system is not
operating in the “Fuel Cut-Off Mode.”
When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulator
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly
as the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine OFF.
16.Check the spark plug associated with a particular
fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. If
checking the spark plug associated with a particular
fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking,
use the following procedure:
Remove the fuel rail, but leave the fuel lines and
injectors connected to the fuel rail. Refer to Fuel
Rail Assembly in On-Vehicle Service.
Lift the fuel rail just enough to leave the fuel
injector nozzles in the fuel injector ports.
Caution: In order to reduce the risk of fire and
personal injury that may result from fuel
spraying on the engine, verify that the fuel rail is
positioned over the fuel injector ports and verify
that the fuel injector retaining clips are intact.
Pressurize the fuel system by connecting a 20
amp fused jumper between B+ and the fuel
pump relay connector.
Visually and physically inspect the fuel
injector nozzles for leaks.
17.A rich condition may result from the fuel pressure
being above 376 kPa (55 psi). A rich condition may
cause a 45 to set. Driveability conditions associatedwith rich conditions can include hard starting
(followed by black smoke) and a strong sulfur smell
in the ex haust.
20.This test determines if the high fuel pressure is due
to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.
21.A lean condition may result from fuel pressure below
333 kPa (48 psi). A lean condition may cause a 44 to
set. Driveability conditions associated with lean
conditions can include hard starting (when the
engine is cold), hesitation, poor driveability, lack of
power, surging, and misfiring.
22.Restricting the fuel return line causes the fuel
pressure to rise above the regulated fuel pressure.
Command the fuel pump ON with the scan tool. The
fuel pressure should rise above 376 kPa (55 psi) as
the fuel return line becomes partially closed.
NOTE: Do not allow the fuel pressure to exceed 414
kPa (60 psi). Fuel pressure in excess of 414 kPa (60
psi) may damage the fuel pressure regulator.
Caution: To reduce the risk of fire and personal
injury:
It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge.
Refer to Fuel Pressure Relief Procedure,
below.
A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before
disconnecting, to catch any fuel that may leak
out. Place the towel in an approved container
when the disconnect is completed.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Located on the intake manifold which is at the top
right part of the engine.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Pressure Gauge Installation
1. Remove the fuel pressure fitting cap.
2. Install fuel pressure gauge 5-8840-0378-0 to the
fuel feed line located on the upper right side of the
engine.
3. Reinstall the fuel pump relay.

ENGINE DRIVEABILITY AND EMISSIONS 6E–151
DIAGNOSTIC TROUBLE CODE (DTC) P0131 O2 SENSOR CIRCUIT LOW
VOLTAGE (BANK 1 SENSOR 1)
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The engine control module (ECM) supplies a bias
voltage of about 450 mV between the heated ox ygen
sensor (HO2S) signal and low circuits. The ox ygen
sensor varies the voltage within a range of about 1000
mV when the ex haust is rich, down through about 10
mV when ex haust is lean. The ECM constantly monitors
the HO2S signal during “Closed Loop” operation and
compensates for a rich or lean condition by decreasing
or increasing injector pulse width as necessary. If theBank 1 HO2S 1 voltage remains ex cessively low for an
ex tended period of time, Diagnostic Trouble Code
P0131 will be set.
Diagnostic Aids
Check for the following conditions:
Heated oxygen sensor wiring - The sensor pigtail
may be routed incorrectly and/or contacting the
exhaust system. Also, check for shorts to ground,
shorts to battery positive and open circuits.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0131 A O
2 SensorCircuit Low Voltage (Bank 1
Se nsor 1)1. No DTC re lating to MAP senso r, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injecto r contro l circuit and ignitio n
co ntro l circuit.
2. Engine coolant temperature is more than
60 de g. C.
3. O
2 sensor bank 1 output voltage is below
50mV in “Closed Loop” condition. “Ope n Lo op” fuel control.

ENGINE DRIVEABILITY AND EMISSIONS 6E–155
DIAGNOSTIC TROUBLE CODE (DTC) P0132 O2 SENSOR CIRCUIT HIGH
VOLTAGE (BANK 1 SENSOR 1)
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The engine control module (ECM) supplies a bias
voltage of about 450 mV between the heated ox ygen
sensor (HO2S) signal and low circuits. The ox ygen
sensor varies the voltage within a range of about 1000
mV when the ex haust is rich, down through about 10
mV when ex haust is lean. The ECM constantly monitors
the HO2S signal during “Closed Loop” operation and
compensates for a rich or lean condition by decreasing
or increasing injector pulse width as necessary. If theBank 1 HO2S 1 voltage remains ex cessively high for an
ex tended period of time, Diagnostic Trouble Code
P0132 will be set.
Diagnostic Aids
Check the following items:
Fuel pressure - The system will go rich if pressure is
too high. The ECM can compensate for some
increase. However, if fuel pressure is too high, a
Diagnostic Trouble Code P0132 may be set. Refer to
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0132 A O
2 Se nsor Circuit High Volta ge (Ba nk 1
Se nsor 1)1. No DTC re lating to MAP senso r, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injecto r contro l circuit and ignitio n
co ntro l circuit.
2. Engine coolant temperature is more than
60 de g. C.
3. O
2 se nsor ba nk 1 output vo lta ge is mo re
than 952mV in “Clo se d Lo op” conditio n. “Ope n Lo op” fuel control.

ENGINE DRIVEABILITY AND EMISSIONS 6E–159
DIAGNOSTIC TROUBLE CODE (DTC) P0134 O2 SENSOR NO ACTIVITY
DEFECTED (BANK 1 SENSOR 1)
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The engine control module (ECM) supplies a bias
voltage of about 450 mV between the heated ox ygen
sensor (HO2S) high and low circuits. The ox ygen
sensor varies the voltage within a range of about 1000
mV when the ex haust is rich, down through about 10
mV when ex haust is lean. The ECM constantly monitors
the HO2S signal during “Closed Loop” operation andcompensates for a rich or lean condition by decreasing
or increasing injector pulse width as necessary. If the
Bank 1 HO2S 1 voltage remains at or near the 450 mV
bias for an ex tended period of time, Diagnostic Trouble
Code P0134 will be set, indicating an open sensor
signal or sensor low circuit.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0134 A O
2 Sensor Circuit No Activity Detecte d
(Ba nk 1 Se nsor 1)1. No DTC re la ting to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injecto r contro l circuit and ignitio n
co ntro l circuit.
2. Engine coolant temperature is more than
60 de g.C.
3. Engine run time is longer than 40 seconds.
4. Ma ss a ir flo w is mo re tha n 7g/s.
5. O
2 se nsor ba nk 1 output vo lta ge is
between 300mV and 600mV.“Ope n Lo op” fuel control.

3B-14 POWER-ASSISTED STEERING SYSTEM


Tie-rod End
If looseness or play is found when checked by moving
the end of ball joint at tie-rod end, replace tie-rod end.

Tie-rod Assembly
If the resistance is insufficient or play is felt when
checked by moving the ball on the tie-rod, replace the
tie-rod assembly.

Rubber Parts
If wear or damage is found through inspection, replace
with new ones.

Reassembly
1. Install mounting rubber and dust cover (If removed).
2. Install oil line.
Torque: 10 - 15 N




m (1.0 – 1.5 kg




m/87 - 130 lb in)
3. Install tie-rod assembly with tab washer.
Apply grease to ball joint, install tie-rod and tab
washer, then tighten to specified torque.
Torque: 69 - 98 N




m (7.0 – 10.0 kg




m/51 - 72 lb ft)
After tightening, bend tab washer against width
across flat of inner ball joint.
4.
Apply a thin coat of grease to the shaft for smooth
installation. Then install bellows.
5. Install band and clip.
6. Install tie-rod end and tighten lock nut.
Torque:
92 - 104 N




m (9.4 – 10.6 kg




m/68 - 77 lb ft)

Main Data and Specifications
General Specifications
2WD 4WD
Power steering Without With
Type Rack and pinion
Rack stroke mm (in) 138 (5.43) 138 (5.43) 152 (5.98)
Steering unit
Lock to lock 4.84 3.38 3.26

3D-2 REAR SUSPENSION
MAIN DATA AND SPECIFICATIONS
General Specifications
Models Standard Heavy-duty Suspension
Items
4
2
(Except High Ride Sus)
4
2
(High Ride Sus)
4

4
4
2 (Except High Ride Sus) 4
2
(High Ride Sus)
4

4
Type Semi-elliptic, rubber bushed, leaf type springs and direct double acting shock
absorbers.


Leaf spring

No. of leaves
5 7
Spring eye type
Berlin eye type Up turned eye type
Bushing outside dia mm(in) Front; 40 (1.57), Rear; 30 (1.18)
Length mm(in) 1200 (47.24)
Width mm(in) 60 (2.36)

Rear shock absorbers
Type

Gas-sealed Hydraulic, double acting telescopic


Mean stroke mm(in)
198 (7.80) 199 (7.83) 198 (7.80) 199 (7.83)
Compressed length mm(in)
323 (12.7) 349 (13.8) 323 (12.7) 349 (13.7)
Extended length mm(in)
521 (20.5) 549 (21.6) 521 (20.5) 549 (21.9)

7D-18 TRANSFER CASE

H-L shift reassembly

1.
Install the shift arm to the shift rod.
2.
Install the spring pin. The top of the pin must be
flush with the surrounding surface (no projection).
3.
Install the front collar, the spring, and the rear colla
r
to the shift block in that order.
4.
Use a socket and a vise to compress the shift block
spring.
5.
Install the inner retaining ring. Be sure that the arm
aperture width is within the specified limit.

226R300014






6.
Install the shift lock assembly to the shift rod.
7.
Use a socket and a vise to compress the H-L shift
spring.
8.
Install the outer snap ring.
9.
Install the guide roller.
2-4 shift ASM


226R300016











2-4 shift disassembly
1.
Remove the guide roller.
2.
Compress the spring and remove the snap ring.
3.
Remove the shift arm.
4.
Remove the spring.
5.
Remove the spring pin.
6.
Remove the shift block assembly.
7.
Remove the shift rod.

Legend

(1) 25.62

(2) 14.1mm Legend

(1) ROD; SHIFT
(2) ARM; SHIFT
(3) SPRING
(4) BLOCK ARM;SHIFT
(5) PIN ARM; SPRING
(6) ROLLER; GUIDE
(7) RING; SNAP