2004 ISUZU TF SERIES stop start

6E–102 ENGINE DRIVEABILITY AND EMISSIONS
9 1. Connect the 5-8840-0378-0 Fuel Injector Tester
and 5-8840-2589-0 Injector Adapter Cable to the
fuel injector harness connector.
2. Set the amperage supply selector switch on the
fuel injector tester to the “Balance Test” 0.5-2.5
amp position.
3. Using the Scan Tool turn the fuel pump ON then
OFF in order to pressurize the fuel system.
4. Record the fuel pressure indicated by the fuel
pressure gauge after the fuel pressure stabilizes.
This is the first pressure reading.
5. Energize the fuel injector by depressing the “Push
to Start Test” button on the fuel injector tester.
6. Record the fuel pressure indicated by the fuel
pressure gauge after the fuel pressure gauge
needle has stopped moving. This is the second
pressure reading.
7. Repeat steps 1 through 6 for each fuel injector.
8. Subtract the second pressure reading from the
first pressure reading for one fuel injector. The
result is the pressure drop value.
9. Obtain a pressure drop value for each fuel injector.
10. Add all of the individual pressure drop values.
This is the total pressure drop.
11. Divide the total pressure drop by the number of
fuel injectors. This is the average pressure drop.
Does any fuel injector have a pressure drop value that
is either higher than the average pressure drop or
lower than the average pressure drop by the specified
value?10kPa
(1.5psi) Go to Step 10Go to OBD
System Check
10 Re-test any fuel injector that does not meet the
specification. Refer to the procedure in Step 11.
NOTE: Do not repeat any portion of this test before
running the engine in order to prevent the engine from
flooding.
Does any fuel injector still have a pressure drop value
that is either higher than the average pressure drop or
lower than the average pressure drop by the specified
value?10kPa
(1.5psi) Go to Step 11Go to
Symptoms
11 1. Replace the faulty fuel injector(s). Refer to Fuel
Injector.
2. Disconnect the 5-8840-2589-0 Injector Adapter
Cable for F/I check and re-connect the original F/I
check connector.
Is the action complete?—Veri fy repai r— Step Action Value(s) Yes No

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.

6E–110 ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Diagnosis
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. Turn the ignition OFF.
2. Turn the air conditioning system OFF.
3. Relieve fuel system pressure and install the fuel
pressure gauge.
4. Turn the ignition ON.
NOTE: The fuel pump will run for approx imately 2
seconds. Use the Scan Tool to command the fuel
pump ON.
5. Observe the fuel pressure indicated by the fuel
pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits?283-376 kPa
(41-55 psi) Go to Step 3Go to Step 17
3 Does the fuel pressure indicated by the fuel pressure
gauge remain constant?
NOTE: The fuel pressure will drop when the fuel
pump stops running, then it should stabilize and
remain constant.—Go to Step 4Go to Step 12
4 1. When the vehicle is at normal operating
temperature, turn the ignition ON to build fuel
pressure and observe the measurement on the
gauge.
2. Start the engine and observe the fuel pressure
gauge.
Did the reading drop by the amount specified after the
engine was started?21-105 kPa
(3-15 psi) Go to Step 5Go to Step 9
5 Is fuel pressure dropping off during acceleration,
cruise, or hard cornering?—Go to Step 6Check for
improper fuel
6 Visually and physically inspect the following items for
a restriction:
The in-line fuel filter.
The fuel feed line.
Was a restriction found?—Verify repair Go to Step 7
7 Remove the fuel tank and visually and physically
inspect the following items:
The fuel pump strainer for a restriction.
The fuel line for a leak.
Verify that the correct fuel pump is in the vehicle.
Was a problem found in any of these areas?—Verify repair Go to Step 8
8 Replace the fuel pump.
Is the action complete?—Veri fy repai r—
9 1. Disconnect the vacuum hose from the fuel
pressure regulator.
2. With the engine idling, apply 12-14 inches of
vacuum to the fuel pressure regulator.
Does the fuel pressure indicated by the fuel pressure
gauge drop by the amount specified?21-105 kPa
(3-15 psi) Go to Step 10Go to Step 11

ENGINE DRIVEABILITY AND EMISSIONS 6E–271
8. If removal of fuel injector is necessary, Refer to Fuel
Injectors Removal Procedure.
Installation Procedure
1. Install the fuel injectors if necessary. Refer to Fuel
Injector Installation Procedure.
2. Install the fuel pressure regulator if necessary. Refer
to Fuel Pressure Regulator Installation Procedure.
3. Place the fuel injector rail assembly on the manifold
and insert the injectors into each port by pushing
fuel rail.
4. Install two fuel rail retaining bolts. Tighten fuel rail
retaining bolt to 19 N·m (1.9kgf·m)
5. Place wiring harness in its place and secure it with
two nuts.
6. Connect all connector to each fuel injector.
7. Connect the fuel supply line securely. Do not over
tighten.8. Connect the fuel return line securely. Do not over
tighten.
9. Connect the negative battery cable.
10. Crank the engine until it starts. Cranking the engine
may take longer than usual due to trapped air in the
fuel system. Check for leak. If fuel leak is observed,
stop engine immediately. Before correcting fuel
leak, be sure to depressurize system again.

HEATER AND AIR CONDITIONING 1-49

OIL RETURN OPERATION
There is close affinity between the oil and the refrigerant.
During normal operation, part of the oil recirculates with the
refrigerant in the system.
When checking the amount of oil in the system, or replacing
any component of the system, the compressor must be run in
advance for oil return operation. The procedure is as follows:
1) Open the all doors and engine hood.
2) Start the engine and A/C switch is "ON" and Set the fan
control knob at its highest position.
3) Run the compressor for more than 20 minutes between
800 and 1,000 rpm in order to operate the system.
4) Stop the engine.


REPLACEMENT OF COMPONENT PARTS
When replacing system component parts, supply the following
amount of oil to the component parts to be installed.

Component parts to be installed Amount of oil
Evaporator 50 cm3 (1.7 fl.oz.)
Condenser 30 cm3 (1.0 fl.oz.)
Receiver/drier 30 cm3 (1.0 fl.oz.)
Refrigerant line (One piece) 10 cm3 (0.3 fl.oz.)

Refrigeration oil must be replenished if more than two parts
are removed at the same time. After installing these
components, check compressor oil.

IMMOBILIZER SYSTEM 11A-13

Immobilizer control unit (ICU);
Mechanical Control Engine (4JA1-T)
Immobilizer control unit (ICU) permits engine starting,
when the security code which compares the securit
y
code registered into the transponder (key) and the
security code registered into ICU, and is similarl
y
registered into ICU and engine immobilizer unit (DDS-1)
is compared and it is judged that it is normal. When the
code registered into the key is unusual, and when not
recognizing a security code, engine immobilizer unit
does not permit starting of engine by the fuel cut valve
on the fuel pump.
The engine immobilizer unit is located with fuel cut
valve on fuel pump 4JA1-T engine.
The immobilizer control unit decides whether there is an
abnormality the security code based on the engine
immobilizer unit security code.
When the problem found, the engine immobilizer unit
stops fuel fupply by the fuel cut valve.




RAW4B0SF000101

POWER-ASSISTED STEERING SYSTEM 3B-7


Power Steering System Test
Test Procedure
F02RX002
Legend
(1) Bolt
(2) Hose
(3) Power Steering Unit
(4) Power Steering Pump


Test of fluid pressure in the power steering system is
performed to determine whether or not the oil pump and
power steering unit are functioning normally.
The power steering system test is used to identify and
isolate hydraulic circuit difficulties. Prior to performing
this test, the following inspections and corrections, i
f
necessary, must be made.


Inspect pump reservoir for proper fluid level.


Inspect pump belt for proper tension.


Inspect pump driver pulley condition.
1. Place a container under the pump to catch the fluid
when disconnecting or connecting the hoses.
2.
With the engine NOT running, disconnect the
pressure hose at the power steering pump and
install power steering tester 5-8840-0135-0 as
shown in the illustration. The gage must be between
the shutoff valve and pump. Open the shutoff valve.
3. Check the fluid level. Fill the reservoir with powe
r
steering fluid, to the "Full" mark. Start the engine,
then turn the steering wheel and momentarily hold it
against a stop (right or left). Turn the engine off and
check the connections at tester for leakage.
4. Bleed the system. Refer to Bleeding the Powe
r
Steering System in this section.
5. Start the engine and check the fluid level. Add
power steering fluid if required. When the engine is
at normal operating temperature, increase engine
speed to 1500 rpm.
CAUTION: Do not leave shutoff valve fully closed
for more than 5 seconds, as the pump could
become damaged internally.

3B-8 POWER-ASSISTED STEERING SYSTEM

6. Fully close the shutoff valve. Record the highest
pressures.


If the pressure recorded is within 9300-9800 kPa
(95-100 kg/cm
2/1350-1420 psi), the pump is
functioning within its specifications.


If the pressure recorded is higher than 9800 kPa
(100 kg/cm
2/1420 psi), the valve in the pump is
defective.


If the pressure recorded is lower than 9300 kPa (95
kg/cm
2/1350 psi), the valve or the rotating group in
the pump is defective.
7. If the pump pressures are within specifications,
leave the valve open and turn (or have someone
else turn) the steering wheel fully in both directions.
Record the highest pressures and compare with the
maximum pump pressure recorded in step 6. If this
pressure cannot be built in either side of the powe
r
steering unit, the power steering unit is leaking
internally and must be replaced.
8. Shut the engine off, remove the testing gauge.
9. Reconnect the pressure hose, check the fluid level
and make the needed repairs.
10. If the problem still exists, the steering and fron
t
suspension must be thoroughly examined.

Maintenance
The hydraulic system should be kept clean and fluid
level in the reservoir should be checked at regula
r
intervals and fluid added when required. Refer to
Recommended Fluids and Lubricants in General
Information section for the type of fluid to be used and
the intervals for filling.
If the system contains some dirt, flush it as described in
this section. If it is exceptionally dirty, the pump must be
completely disassembled before further usage. (The
steering unit cannot be disassembled.)
All tubes, hoses, and fittings should be inspected for
leakage at regular intervals. Fittings must be tight. Make
sure the clips, clamps and supporting tubes and hoses
are in place and properly secured.
Power steering hoses and lines must not be twisted,
kinked or tightly bent. Air in the system will cause
spongy action and noisy operation. When a hose is
disconnected or when fluid is lost, for any reason, the
system must be bled after refilling. Refer to Bleeding the
Power Steering System in this section.


Inspect belt for tightness.


Inspect pulley for looseness or damage. The pulle
y
should not wobble with the engine running.


Inspect hoses so they are not touching any othe
r
parts of the vehicle.


Inspect fluid level and fill to the proper level.

Fluid Level
1. Run the engine until the power steering fluid
reaches normal operating temperature, about 55
C (130
F), then shut the engine off.
2. Check the level of fluid in the reservoir.
3. If the fluid level is low, add power steering fluid as
specified in General Information to the proper level
and install the receiver cap.
4. When checking the fluid level after the steering
system has been serviced, air must be bled from
the system. Refer to Bleeding the Power Steering
System in this section.

Bleeding The Power Steering System
When a power steering pump or unit has been installed,
or an oil line has been disconnected, the air that has
entered the system must be bled out before the vehicle
is operated. If air is allowed to remain in the powe
r
steering fluid system, noisy and unsatisfactory operation
of the system may result.

Bleeding Procedure
When bleeding the system, and any time fluid is added
to the power steering system, be sure to use only powe
r
steering fluid as specified in General Information.
1. Fill the pump fluid reservoir to the proper level and
let the fluid settle for at least two minutes.
2. Start the engine and let it run for a few seconds. Do
not turn the steering wheel. Then turn the engine
off.
3. Add fluid if necessary.
4. Repeat the above procedure until the fluid level
remains constant after running the engine.
5. Raise and support the front end of the vehicle so
that the wheels are off the ground.
6. Start the engine. Slowly turn the steering wheel right
and left, lightly contacting the wheel stops.
7. Add power steering fluid if necessary.
8. Lower the vehicle, set the steering wheel at the
straight forward position after turning it to its full
steer positions 2 or 3 times, and stop the engine.
9. Check the fluid level and refill as required.
10. If the fluid is extremely foamy, allow the vehicle to
set a few minutes, then repeat the above procedure.

Flushing The Power Steering System
1. Raise and support the front end of the vehicle off
the ground until the wheels are free to turn.
2. Remove the fluid return line at the pump inlet
connector and plug the connector port on the pump.
Position the line toward a large container to catch
the draining fluid.
3. While running the engine at idle, fill the reservoi
r
with new power steering fluid. Turn the steering
wheel in both directions. Do not contact or hold the
steering wheel to the wheel stops. This will cause
the pump to go to pressure relief mode, which ma
y
cause a sudden fluid overflow at the reservoir.