power steering ISUZU TF SERIES 2004 Owner's Guide

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-53
Idle Air Control (IAC) Valve








Step
CoilAB CD
Coil A High
(EC M B13)On On
Coil A Low
(EC M B16)On On
Coil B High
(EC M B14)On On
Coil B Low
(EC M B17)On On

(IAC Valve Close Direction)
(IAC Valve Open Direction)



The idle air control valve (IAC) valve is two directional
and gives 2-way control. It has a stepping moto
r
capable of 256 steps, and also has 2 coils. With power
supply to the coils controlled steps by the engine control
module (ECM), the IAC valve's pintle is moved to adjus
t
idle speed, raising it for fast idle when cold or there is
extra load from the air conditioning or power steering.
By moving the pintle in (to decrease air flow) or out (to
increase air flow), a controlled amount of the air can
move around the throttle plate. If the engine speed is
too low, the engine control module (ECM) will retract the
IAC pintle, resulting in more air moving past the throttle
plate to increase the engine speed.
If the engine speed is too high, the engine control
module (ECM) will extend the IAC pintle, allowing less
air to move past the throttle plate, decreasing the
engine speed.

The IAC pintle valve moves in small step called counts.
During idle, the proper position of the IAC pintle is
calculated by the engine control module (ECM) based
on battery voltage, coolant temperature, engine load,
and engine speed.
If the engine speed drops below a specified value, and
the throttle plate is closed, the engine control module
(ECM) senses a near-stall condition. The engine control
module (ECM) will then calculate a new IAC pintle valve
position to prevent stalls. If the IAC valve is disconnected and reconnected with
the engine running, the idle speed will be wrong. In this
case, the IAC must be reset. The IAC resets when the
key is cycled "On" then "Off". When servicing the IAC, i
t
should only be disconnected or connected with the
ignition "Off".
The position of the IAC pintle valve affects engine start-
up and the idle characteristic of the vehicle.
If the IAC pintle is fully open, too much air will be
allowed into the manifold. This results in high idle
speed, along with possible hard starting and lean
air/fuel ratio.

Camshaft Position (CMP) Sensor








12
(1) Camshaft Position (CMP) Sensor
(2) EGR Valve


With the use of sequential multi-point fuel injection, a
hall element type camshaft position (CMP) is adopted to
provide information to be used in making decisions on
injection timing to each cylinder. It is mounted on the
rear of the left-hand cylinder head and sends signals to
the ECM.
One pulse is generated per two rotations of crankshaft.

6E-80 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
Parameter
Units Idle 2000rpm Definitions
23 A/C Request (Air
Conditioning) On/Off Off Off This displays the air conditioner request signal. This should display "On" when the air
conditioner switch is switched on.
24 A/C Clutch On/Off Off Off This displays whether the ECM has commanded the A/C compressor clutch "On" or
"Off".
25 EVAP Purge
Solenoid
(Evaporative
Emission) % 50
80 0 This displays the duty signal from the ECM to control the canister purge solenoid
valve.
26 Fuel Trim Cell 49
52 13
17 This displays dependent on engine speed and MAF sensor reading.
A plot of engine speed versus MAF amount is divided into the cells.
Fuel trim cell indicates which cell is currently active.
27 Fuel Pump On/Off On On This displays operating status for the fuel pump main relay.
This should display "On" when the key switch is turned on and while engine is
running.
28 Deceleration Fuel
Cutoff Active/ Inactive Inactive Inactive The ECM will command the deceleration fuel mode when it detects a closed throttle
position while the vehicle is traveling.
While in decreasing fuel mode, the ECM will decrease the amount of fuel delivered
by entering open loop and decreasing the injector pulse width.
29 Power Enrichment Yes/No No No The ECM will command power enrichment mode "Yes" when a large increase in
throttle position and load is detected.
While in power enrichment mode, the ECM will increase the amount of fuel delivered
by entering open loop and increasing the injector pulse width.
30 Vehicle Speed km/h or mph 0 0 This displays vehicle speed.
The vehicle speed is measured by ECM from the vehicle speed sensor.
31 Cam Signal Present/ Missing Present Present This displays input signal from the camshaft position sensor.
When the correct pulse is generated, signal is received.
32 PSP Switch
(Power Steering
Pressure) Normal Pressure /
High Pressure Normal PressureNormal PressureThis displays the power steering pressure signal.
This should display "High Pressure" when the steering is steered.
33 Security Code
Status Programmable/
Not
Programmable Programmable Programmable This should display "Programmable" when the correct security code & secret code
are programmed.
34 Security Code Okay/ Not Okay Okay Okay This should display "Okay" when the security code is correctly accepted.
35 Immobilizer
System Normal /
Abnormal Normal Normal This should display "Normal" when the immobilizer is correctly operated.
36 Malfunction
Indicator Lamp On/Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is turned on.
37 Time From Start   This displays the engine time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to 00:00:00

6A-18 ENGINE MECHANICAL (C24SE)
OPERATIONS ON ENGINE AGGREGATES
Engine Damping Blocks (Engine Without
Transmission)
Removal
1. Remove bonnet.
2. Remove radiator.
3. Remove air inlet hose.
4. Remove power steering pump drive belt and power
steering pump from engine.


5. Remove all cable connections, hoses and lines from
engine.
6. Remove accelerator cable from inlet pipe.


7. Remove exhaust pipe from manifold.



8. Remove lower nine bolts and transmission from engine
block.
9. Remove clutch slave cylinder and allow to hang free.
10. Remove starter from engine block.

11. Remove upper bolts of left and right engine mounting
from damping blocks.
12. Raise engine slightly.
13. Remove lower bolts of left and right damping blocks.
14. Remove damping blocks.

6A-20 ENGINE MECHANICAL (C24SE)





6. Install power steering pump and V-belt.

Adjust
Adjust power steering pump V-belt tension according to the
corresponding operation.


Installation
7. Install radiator according to the corresponding operation.
8. Install air inlet hose.
9. Install all electrical cable connections, hoses and lines to
engine.
10. Install accelerator cable from inlet pipe.
11. Install bonnet.


Inspection
1. Check engine oil level.
2. Fill up cooling system and bleed according to the
corresponding operation.

ENGINE MECHANICAL (C24SE) 6A-21

Toothed Belt and Timing Check

Removal
1. Remove the belts on the bracket for alternator.
2. Remove the fan.
3. Remove the V-belt for power steering.
4. Remove the V-belt for A/C.
5. Remove the fan belt.
6. Remove the fan shroud.

7. Remove the crankshaft pulley while counterholding on
the fastening bolt of toothed belt drive gear.
8. Remove the toothed belt from cover.

Inspection
1. Turn the crankshaft in the engine rotational direction
mark(2) so that the notch (1) on the camshaft gear aligns
with the mark on toothed belt rear cover.
2. Check the timing belt for worn, cracks or oil adhesion.

3. Check that the cast on the water pump aligns with the
counterpart on cylinder block (arrowed).
4. The tension of a toothed belt is correctly adjusted when
the pointer and the center of the notch are aligned(I).
The tension of a run-in toothed belt (regardless of
mileage covered) is correctly adjusted when the pointer
is positioned approx. 4mm (0.16 in.) to the left of the
center of the notch(II).
Check the condition of the run-in toothed belt for
suitability for reuse. Only toothed belts of the toothed
belt tension rollers must be replaced and the source of oil
contamination must be eliminated.

6A-22 ENGINE MECHANICAL (C24SE)


Installation
1. Install the toothed belt to the cover.
2. Install the crankshaft pulley while counterholding on the
fastening bolt of toothed belt drive gear.
3. Install the fan shroud.


Tighten(Torque)
Crankshaft pulley bolts - 20 N

m (2.1 kgf

m)


4. Install the fan belt
5. Install the V-belt for A/C.
6. Install the V-belt for power steering.
7. Install the fan.
8. Install the belts on the bracket for alternator.

6A-24 ENGINE MECHANICAL (C24SE)
Toothed Belt, Replace
(Engine with toothed belt tension
roller)

Removal
1. Remove the belts on the bracket for alternator.
2. Remove the fan.
3. Remove the V-belt for power steering.
4. Remove the V-belt for A/C.
5. Remove the fan belt.
6. Remove the fan shroud.


7. Remove the crankshaft pulley while counterholding on
the fastening bolt of toothed belt drive gear.
8. Remove the toothed belt from cover.


Adjust
Turn the crankshaft in the engine rotational direction to
mark(2).
Align markings on toothed belt and on toothed belt rear cover.
Simultaneously, notch (1) on camshaft gear must align with the
mark on toothed belt rear cover.
Turn the crankshaft slowly and smoothly.

ENGINE MECHANICAL (C24SE) 6A-25








Adjust
Loosen the fastening bolt of the toothed belt tension roller and
turn the adjustment eccentric in the direction of arrow
(clockwise) until pointer (1) comes to the left stop.
Remove the toothed belt.

Installation
1. Install a new toothed belt while keeping tension side taut.

Adjust
Toothed belt tension - see operation " Toothed Belt Tension".


2. Install the toothed belt to the cover.
3. Install the crankshaft pulley while counterholding on the
fastening bolt of toothed belt drive gear.
4. Install the fan shroud.
5. Install the fan belt.
6. Install the V-belt for A/C.
7. Install the V-belt for power steering.
8. Install the fan.
9. Install the belts to the bracket for alternator.

ENGINE MECHANICAL (C24SE) 6A-39







Camshaft Housing, Check for Plane Surface
Clean
Sealing surfaces.

Inspection
Check length and width of sealing surface for deformation and
diagnosis for warpage and use straight edge feeler gauge.

Measure
Height of camshaft housing (sealing surface to sealing
surface).
Dimension I: (74.0 mm)



Cylinder Head, Removal and Installation
Important
Only remove cylinder head with engine cold (room
temperature).




Removal
1. Remove the alternator, power steering and V-belts.



Removal
2. Loosen the fastening bolts from alternator.
3. Loosen the lower alternator fastening bolt by swinging
the alternator to the rear.



Removal
4. Remove the front toothed belt cover.
5. Remove the toothed belt from camshaft pulley.
See operation "Timing Check and Adjust".

6A-42 ENGINE MECHANICAL (C24SE)


Installation
1. Install the fastening bolts.
2. Loosen the lower alternator fastening bolt.
3. Install the alternator, power steering and V-belts.



Cylinder Head, Disassemble and Assemble
Removal
1. Remove the hydraulic valve lifters.
Lay aside in installation positions.
2. Remove the spark plugs, exhaust manifold and intake
manifold from cylinder head.




Removal
1. Mark valves.
2. Remove the tension valve springs with 5-8840-2594-0
(1).
3. Remove valve keepers, valve spring cap and valve
spring.



Removal
1. Remove the valve and valve stem seal.
2. Remove the valve spacer ring (1-exhaust) and valve
spring seat (2-intake).
3. Remove valve from cylinder head.

Clean
Sealing surfaces.