spark plugs replace ISUZU TF SERIES 2004 User Guide

6E-358 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
12
Check the fuel pressure. Refer to Fuel System
Diagnosis.
Was a problem found?
- Verify repair Go to Step 13
13
Monitor "B1S1 (Bank 1 Sensor 1) Status" and "B2S1
(Bank 2 Sensor 1) Status" on the Tech 2.
Is the "B1S1 (Bank 1 Sensor 1) Status" or "B2S1
(Bank 2 Sensor 1) Status" in the lean condition?
- Go to Step 14 Go to Step 15
14
Check items that can cause the engine to run lean.
Refer to DTC P0171 "O2 Sensor System Too Lean
(Bank 1)" or DTC P0174 "O2 Sensor System Tool
Lean (Bank 2)".
Was a problem found?
- Verify repair Go to Step 15
15
Check spark plugs for proper heat range.
Were incorrect spark plugs installed?
- Verify repair Go to Step 16
16
1. Remove excessive carbon buildup with a top
engine cleaner.
2. Re-evaluate vehicle performance.
Is detonation still present?
- Verify repair Go to Step 17
17
Check for an engine mechanical problem. Perform a
cylinder compression check. Refer to Engine
Mechanical.
Was a problem found?
- Verify repair Go to Step 18
18
1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection.

Tech 2 data.

All electrical connections within a suspected circuit
and/or system.
Was a problem found?
- Verify repair Go to Step 19
19
Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the "SPS (Service Programming System)".
Was the problem solved?
- Verify repair Go to Step 20
20
Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual. Following
ECM programming, the immobilizer system (if
equipped) must be linked to the ECM. Refer to section
11 “Immobilizer System-ECM replacement” for the
ECM/Immobilizer linking procedure.
- Verify repair -

6E-380 3.5L ENGINE DRIVEABILITY AND EMISSIONS
SPARK PLUGS

Removal Procedure
1. Remove spark plugs.

Inspection Procedure
The spark plug affects entire engine performance and
therefore its inspection is very important.
 Check electrode and insulator for presence o
f
cracks, and replace if any.
 Check electrode for wear, and replace if necessary.
 Check gasket for damage, and replace if necessary.
 Measure insulation resistance with an ohmmeter,
and replace if faulty.
 Adjust spark plug gap to 1.0 mm (0.04 in)

1.1 mm
(0.043 in).
 Check fuel and electrical systems if spark plug is
extremely dirty.
 Use spark plugs having low heat value (hot type
plug) if fuel and electrical systems are normal.
 Use spark plugs having high heat value (cold type
plug) if insulator and electrode are extremely
burned.
Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and
insulator of spark plug reduces the engine performance.
Possible causes:
 Too rich mixture
 Presence of oil in combustion chamber
 Incorrectly adjusted spark plug gap
Burning Electrodes
This fault is characterized by scorched or heavily
oxidized electrode or blistered insulator nose.
Possible causes:
 Too lean mixture
 Improper heat value

Measuring Insulation Resistance
 Measure insulation resistance using a 500 volt
megaohm meter.
 Replace spark plugs if measured value is out o
f
standard.
Insulation resistance: 50 M
  or more




011RS010
Cleaning Spark Plugs
 Clean spark plugs with a spark plug cleaner.
 Raise the ground electrode to an angle of 45 to 60
degrees. If electrode is wet, dry it before cleaning.

After spark plug is thoroughly cleaned, check
insulator for presence of cracks.
 Clean threads and metal body with a wire brush.
 File the electrode tip if electrode is extremely worn.

ENGINE DIAGNOSIS (C24SE) 6-3
3.Trouble in Fuel System
Condition Possible cause Correction
Starting motor turns over and
spark occurs but engine does not
start. Fuel tank empty Fill
Water in fuel system Clean
Fuel filter clogged Replace filter
Fuel pipe clogged Clean or replace
Fuel pump defective Replace
Fuel pump circuit open Correct or replace
Evaporative Emission Control
system circuit clogged Correct or replace
Multiport Fuel Injection System
faulty Refer to "Electronic Fuel Injection"
section
4.Engine Lacks Compression
Condition Possible cause Correction
Engine lacks compression Spark plug loosely fitted or spark
plug gasket defective Tighten to specified torque or
replace gasket
Spark plug wire incorrect Connect properly or replace
Valve timing incorrect Adjust
Cylinder head gasket defective Replace gasket
Valve incorrectly seated Lap valve
Valve stem seized Replace valve and valve guide
Valve spring weakened Replace
Cylinder or piston rings worn Overhaul engine
Piston ring seized Overhaul engine.

Engine Compression Test Procedure
1. Start and run the engine until the engine
reaches normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and
fuse box. 6. Engage the starter and check that the cranking
speed is approximately 300 rpm.
7. Install cylinder compression gauge into spark
plug hole.
8. With the throttle valve opened fully, keep the
starter engaged until the compression gauge
needle reaches the maximum level. Note the
reading.
9. Repeat the test with each cylinder.
The pressure difference between the individual
cylinders should not exceed 100kPa (14.5 psi).

ENGINE DIAGNOSIS (C24SE) 6-5
Rough Engine Running
Condition Possible cause Correction
Engine misfires regularly Ignition coil layer shorted Replace
Spark plugs fouling Clean or install hotter type plug
Spark plug(s) insulator nose
leaking Replace
Spark plug wire incorrect Connect properly or replace
Fuel injector(s) defective Replace
Engine control module faulty Replace
Engine knocks regularly Spark plugs running too hot Install colder type spark plugs
Powertrain control module faulty Replace
Engine lacks power Spark plugs fouled Clean
Spark plug wire incorrect Connect properly or replace
Fuel injectors defective Replace
Manifold Absolute Pressure
(MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defective Correct or replace
Engine Coolant Temperature
Sensor or Engine Coolant
Temperature Sensor circuit
defective Correct or replace
Engine Control Module faulty Replace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defective Correct or replace
Throttle Position Sensor or
Throttle Position Sensor circuit
defective Correct or replace
Knock Sensor or Knock Sensor
circuits defective Correct or replace
Knock Sensor Module or Knock
Sensor Module circuits defective Correct or replace

ENGINE DIAGNOSIS (C24SE) 6-7
Engine Lacks Power
Condition Possible cause Correction
Trouble in fuel system Fuel Pressure Control Valve not
working normally Replace
Fuel injector clogged Clean or replace
Fuel pipe clogged Clean
Fuel filter clogged or fouled Replace
Fuel pump drive circuit not
working normally Correct or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative
Emission Control System circuit Clean or replace
Water in fuel system Clean
Inferior quality fuel in fuel system Use fuel of specified octane rating
Engine Control Module supplied
poor voltage Correct circuit
Throttle Position Sensor cable
disconnected or broken Correct or replace
Throttle Position Sensor defective Replace
Manifold Absolute Pressure
Sensor not working normally Replace
Intake Air Temperature sensor not
working normally Replace
Engine Coolant Temperature
Sensor circuit open or shorted Correct or replace
Engine Coolant Temperature
Sensor defective Replace
Engine Control Module defective Replace
Trouble in intake or exhaust
system Air Cleaner Filter clogged Replace filter element
Air duct kicked or flattened Correct or replace
Ignition failure
- Refer to Hard Start
Troubleshooting Guide
Heat range of spark plug
inadequate Install spark plugs of adequate
heat range
Electronic Ignition System with
module Replace

6-10 ENGINE DIAGNOSIS (C24SE)
Troubleshooting Procedure

Condition Possible cause Correction
Piston pin noise
(Piston makes noise each time it
goes up and down) Piston pin or piston pin hole worn Replace piston, piston pin and
connecting rod assy

Troubleshooting Procedure
The slapping sound stops when spark plug on bad
cylinder is shorted out.

Condition Possible cause Correction
Timing belt noise Timing belt tension is incorrect Replace pusher or adjust the
tension pulley or replace timing
belt
Tensioner bearing defective Replace
Timing belt defective Replace
Timing wheels defective Replace
Timing belt comes in contact with
timing cover Replace timing belt and timing
cover
Valve noise Valve and valve guide seized Replace valve and valve guide
Valve spring broken Replace
Valve seat off-positioned Correct
Crankshaft noise Crankshaft end play excessive
(noise occurs when clutch is
engaged) Replace thrust bearing
Engine knocking Preignition due to use of spark
plugs of inadequate heat range Install Spark Plugs of adequate
heat range
Fuel too low in octane rating Replace fuel
Wide Open Throttle enrichment
system failure Refer to Section 6E
Selection of transmission gear
incorrect Caution operator or incorrect gear
selection
Engine overheating Refer to "Engine Lacks Power"
Others Water pump defective Replace
V-belt slipping Adjust tension of V-belt or replace
V-belt

ENGINE MECHANICAL (C24SE) 6A-13
Valve System C24SE
Actuation Type Direct-acting Inverted Bucked Tappet
Valve Clearance Adjustment Hydraulic
Valve Rotor Type None
Inlet-Valve Material Chromium Alloyed Steel
-Seat Insert Material Sintered Iron
Exhaust-Valve Material Head: Cr-Mn-Ni Alloyed Shaft: Cr-Si Alloyed &Cr plated
-Seat Insert Material Sintered Iron
Valve Spring Material GME 06 100-C1
Valve Guide Material QS 13 MR 00
Valve Seal Type Lip

Water Pump C24SE
Type Centrifugal
Drive-Material &Type HNBR Toothed-belt
Bearing Type Double Row Ball
Shaft Seal Type Mechanical Ceramic

Thermostat-Coolant C24SE
Type Bypass

Oil Pump & Filter C24SE
Type Gear Pump
Location Front of Engine
Drive Direct Crankshaft Driven
Filter Type Full Flow with Bypass for blocked filter

Oil & Oil Reservoir C24SE
Reservoir-Description & Location 1-piece below Engine
Reservoir Material Aluminum Alloy (pressure cast)
Replacement Oil Fill Volume
-With Filter change 4.25liters
-Without Filter change 4.00liters
Recommended Oil-Run-in 10W/30SG
-Service (above-18C) 10W/40SG
-Service (below-18C) 5W/30SG
Oil Classification API&CCMC

Ignition Components C24SE
Spark Plugs Conventional
Type Electronic Spark Control
No. of Coils &Type 2 Solid State
Coil Location Engine-mounted
Ignition Lead Type Inductive (hi-resistance)

ENGINE MECHANICAL (C24SE) 6A-37


Hydraulic Valve Lifters, Replace
Removal
1. Remove the spark plug connectors and spark plugs.
2. Remove the camshaft housing cover.


Removal
3. Turn the crankshaft at fastening bolt of toothed belt drive
gear in the direction of the engine rotation until the cam
of hydraulic valve lifter being replaced stands vertically.


Removal
4. Apply 5-8840-0457-0 to the camshaft housing, valve
spring cap and tension valve spring.


Removal
5. Remove the cam follower from camshaft housing.
Note thrust pieces.
6. Remove hydraulic valve lifter from camshaft housing.



Camshaft Housing, Replace
Removal
Cylinder head-see operation “Cylinder Head. Remove and
Install”.

IGNITION SYSTEM 6D2-3







Spark Plug
Removal
1. Remove spark plugs.
Inspection and Repair
The spark plug affects entire engine performance and
therefore its inspection is very important.


Check electrode and insulator for presence of cracks, and
replace if any.


Check electrode for wear, and replace if necessary.


Check gasket for damage, and replace if necessary.


Measure insulation resistance with an ohmmeter, and
replace if faulty.

Adjust spark plug gap to 1.0 - 1.1 mm (0.027 in) - 0.8 mm
(0.031 in).


Check fuel and electrical systems if spark plug is extremel
y
dirty.


Use spark plugs having low heat value (hot type plug) if fuel
and electrical systems are normal.


Use spark plugs having high heat value (cold type plug) i
f
insulator and electrode are extremely burned.



Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and insulator of
spark plug reduces the engine performance.
Possible causes:


Too rich mixture


Presence of oil in combustion chamber


Incorrectly adjusted spark plug gap



Burning Electrodes
This fault is characterized by scorched or heavily oxidized
electrode or blistered insulator nose.
Possible causes:



Too lean mixture


Improper heat value




Measuring Insulation Resistance


Measure insulation resistance using a 500 volt megaohm
meter.

Replace spark plugs if measured value is out of standard.
Insulation resistance: 50 M

  or more

6E–54 ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR ELECTRIC
IGNITION SYSTEM
The engine use two ignition coils, one per two cylinders.
A two wire connector provides a battery voltage primary
supply through the ignition fuse.
The ignition control spark timing is the ECM’s method of
controlling the spark advance and the ignition dwell.
The ignition control spark advance and the ignition dwell
are calculated by the ECM using the following inputs.
Engine speed
Crankshaft position (CKP) sensor
Engine coolant temperature (ECT) sensor
Throttle position sensor
Vehicle speed sensor
ECM and ignition system supply voltage
Ignition coil works to generate only the secondary
voltage be receiving the primary voltage from ECM.
The primary voltage is generated at the coil driver
located in the ECM. The coil driver generate the primary
voltage based on the crankshaft position signal. In
accordance with the crankshaft position signal, ignition
coil driver determines the adequate ignition timing and
also cylinder number to ignite.
Ignition timing is determined the coolant temperature,
intake air temperature, engine speed, engine load,
knock sensor signal, etc.
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequently fail at higher
engine speeds. Faulty spark plugs may cause poor fuel
economy, power loss, loss of speed, hard starting and
generally poor engine performance. Follow the
scheduled maintenance service recommendations to
ensure satisfactory spark plug performance. Refer to
Maintenance and Lubrication.
Normal spark plug operation will result in brown to
grayish-tan deposits appearing on the insulator portion
of the spark plug. A small amount of red-brown, yellow,
and white powdery material may also be present on the
insulator tip around the center electrode. These
deposits are normal combustion by-products of fuels
and lubricating oils with additives. Some electrode wear
will also occur. Engines which are not running properly
are often referred to as “misfiring.” This means the
ignition spark is not igniting the air/fuel mix ture at the
proper time. While other ignition and fuel system causes
must also be considered, possible causes include
ignition system conditions which allow the spark voltage
to reach ground in some other manner than by jumping
across the air gap at the tip of the spark plug, leaving
the air/fuel mix ture unburned. Misfiring may also occur
when the tip of the spark plug becomes overheated and
ignites the mixture before the spark jumps. This is
referred to as “pre-ignition.”
Spark plugs may also misfire due to fouling, ex cessive
gap, or a cracked or broken insulator. If misfiring occursbefore the recommended replacement interval, locate
and correct the cause.
Carbon fouling of the spark plug is indicated by dry,
black carbon (soot) deposits on the portion of the spark
plug in the cylinder. Ex cessive idling and slow speeds
under light engine loads can keep the spark plug
temperatures so low that these deposits are not burned
off. Very rich fuel mix tures or poor ignition system output
may also be the cause. Refer to DTC P1167.
Oil fouling of the spark plug is indicated by wet oily
deposits on the portion of the spark plug in the cylinder,
usually with little electrode wear. This may be caused by
oil during break-in of new or newly overhauled engines.
Deposit fouling of the spark plug occurs when the
normal red-brown, yellow or white deposits of
combustion by-products become sufficient to cause
misfiring. In some cases, these deposits may melt and
form a shiny glaze on the insulator around the center
electrode. If the fouling is found in only one or two
cylinders, valve stem clearances or intake valve seals
may be allowing ex cess lubricating oil to enter the
cylinder, particularly if the deposits are heavier on the
side of the spark plug facing the intake valve.
Ex cessive gap means that the air space between the
center and the side electrodes at the bottom of the
spark plug is too wide for consistent firing. This may be
due to improper gap adjustment or to ex cessive wear of
the electrode during use. A check of the gap size and
comparison to the gap specified for the vehicle in
Maintenance and Lubrication will tell if the gap is too
wide. A spark plug gap that is too small may cause an
unstable idle condition. Ex cessive gap wear can be an
indication of continuous operation at high speeds or
with engine loads, causing the spark to run too hot.
Another possible cause is an ex cessively lean fuel
mixture.