ISUZU TROOPER 1995 Workshop Manual

IGNITION SYSTEM 604 - 3
ON-VEHICLE SERVICE
SPARK PLUG WIRES
EJ REMOVAL
Preparation
• Disconnect battery ground cable.
1. Spark plug wires (Fig. 604-2)
Fig. 6D4-2
(1!] INSPECTION AND REPAIR
Check the high tension cable for insulation. Check
terminals for corrosion or damage, and replace as
necessary.
Measuring resistance of spark plug wires (kQ)
Spare plug wires SOHC DOHC
No.1 cable 6.4-14.9 6.2-14.2
No.2 cable 5.7-13.1 7.2-16.7
No.3 cable 6.2-14.4 6.5-14.9
No.4 cable 5.8-13.3 6.8-15.8
No.5 cable 6.4-14.9 6.9-16.0
No.6 cable 6.9-16.0 6.3-14.5
Measure resistance
of spark plug wires, and replace
the cable if its value exceeds the standard. (Fig. 6D4-
3)
Fig. 6D4-3
B INSTALLATION
1. Spark plug wires
• Connect ignition coils and spark plugs with
spark plug wires respectively. Match each
number (cylinder No.) marked on the ignition
coil with that on spark plug wire, and connect
each spark
plug for the cylinder. (Fig. 6D4-4)
LH bank
y Front
#4-­
#1--
1®®®1
RH Bank
Connecting Position of Spark plug wire
Fig. 6D4-4
• Connect battery ground cable.
"f CAUTION
Do not cross, twist or pull the spark plug wires.
SPARK PLUG
EJ REMOVAL
1. Spare plug wires
2. Spark plugs (Fig. 604-5)

604-4 IGNITION SYSTEM
Fig. 604A-5
~ INSPECTION AND REPAIR
The spark plug affects entire engine performance and
therefore its inspection is very important.
• Check electrode and insulator for presence of
crack, and replace if any.
• Check electrode for wear, and replace if neces­
sary.
• Check gasket for damage, and replace if neces­
sary.
• Measure insulation resistance with an ohmmeter,
and replace if faulty.
• Adjust spark plug gap to 1.0(0.04) -1.1 (0.043)
mm(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 perfor­
mance.
Possible causes:
• Too rich mixture
• Retarded ignition timing
• 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
• Advanced ignition timing
• Improper heat value
Measuring Insulation Resistance
• Measure insulation resistance using a 500 volt
megaohm meter. (Fig. 604-6)
Fig.
604-6
• Replace spark plugs if measured value is out of
standard.
I @!.j Insulation resistance MQ 50 or more
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 crack.
• Clean threads and metal body with a wire brush.
• File the electrode tip if electrode is extremely
worn.
• Bend the ground electrode to adjust the spark
plug gap. (Fig. 604-7)
Fig. 604-7
•

[!!) INSTALLATION
2. Spark plugs
• Tighten spark plugs to the specified torque.
1. Spark plug wires
• Connect high tension cables to correct termi­
nals respectively.
~~~ Torque N·m (lb·ft) I
ELECTRONIC IGNITION (EI)
ASSEMBLY
EJ REMOVAL
Preparation
• Disconnect battery ground cable
1. Spark plug wires
2. Wiring connectors
18 (13)
• Disconnect connectors on Engine Control
Module (ECM), power supply and crank angle
sensor.
3. Electronic Ignition (EI) assembly
• Remove three fixing bolts, then the El assem­
bly. (Fig. 6D4-8)
Fig. 6D4-8
E]INSTALLATION
Electronic Ignition (Ell assembly
3. Electronic Ignition (EI) assembly
~~~ Torque N·m (lb·ftl I 19 (14)
2. Wiring connector
Connect connectors to ECM, power supply and
crank
angle sensor.
IGNITION SYSTEM 604-5
1. Spark plug wires
• Connect Spark plug wires to correct terminals.
• Connect battery ground cable.
CRANKSHAFT POSITION SENSOR
(CKP Sensor)
E) REMOVAL
Preparation
• Disconnect battery ground cable
•
Remove exhaust & transfer protector
• Disconnect front propeller shaft joint. (Fig.
6D4-9)
Fig. 6D4-9
1. Wiring connector
2. Mounting nut
3. Crankshaft position sensor (CKP sensor) (Fig.
604-10)
Fig. 6D4-10

604-6 IGNITION SYSTEM
B INSTALLATION
3. Crankshaft Position Sensor (CKP sensor)
• Install crankshaft position sensor into the cyl­
inder block.
1~1 Before installation, apply small amount of en­
gine oil to the 0-ring.
~~~ Torque N-m (lb-in) I 10 (87)
2. Mounting bolt
• Tighten the bolt to the specified torque.
~~~ Torque N-m (lb·ft) I 63 (46)
TORQUE SPECIFICATIONS
Electronic Ignition (EI) assembly
1. Wiring connector
• Connect front propeller shaft joint and tighten
to the specified torque.
• Connect battery ground cable.
•
Tighten the exhaust & transfer protector fixing
bolt to the specified torque
~~~ Torque N-m (lb·ft) 37 (27)
N·m (lb·ftl
Spark plug
Exhaust & transfer protector
Crankshaft Position sensor
Fig. 604-11
•

IGNITION SYSTEM 604-7
MAIN DATA AND SPECIFICATIONS
Ignition System
Ignition Form Electronic Ignition System (EI system) with
Crankshaft Position Sensor (CKP sensor)
Spark
Plug
Type FR2LS. BKRSE-11. K20PR-U 11
FR3LS. BKRSE-11. K 16PR-U 11
Plug gap mm (in) 1.0 (0.04) -1.1 (0.043)
Torque N·m Ob·ft) 19 (14)

MEMO

DRIVEABILITV AND EMISSIONS 6E2-1
SECTION 6E2
DRIVEABILITV AND EMISSION
CONTENTS
Driveability and Emission General Section B-
Information ....................... 6E2- 2 Driveability Symptoms . . . . . . . . . . . 6E2-89
Section
A-Section C-
Engine Components/Wiring Diagrams/ Component Systems . . . . . . . . . . . . . 6E2-99
Diagnostic
Charts ................. 6E2-23

6E2-2 DRIVEABILITY AND EMISSIONS
DRIVEABILITV AND EMISSIONS GENERAL INFORMATION
CONTENTS
General Information
Driveability ....................... .
Emissions
........................ .
Maintenance
Schedule .............. .
Introduction ...................... .
Electronic Engine
Control .......... .
What This Section Contains ........ .
Blocking Drive Wheels
Visual/Physical
Underhood Inspection
6E2-3
6E2-3
6E2-3
6E2-3
6E2-3
6E2-3
6E2-3
6E2-3
Basic
Knowledge required . . . . . . . . . . . . 6E2-4
Basic Electric Circuits . . . . . . . . . . . . . .
6E2-4
Use
of Circuit Testing Tools . . . . . . . . . 6E2-4
Use
of Digital Volt-Ohm Meter (DVOM). 6E2-4
Diagnostic
Information . . . . . . . . . . . . . . . 6E2-4
"Check Engine" Malfunction Indicator
Lamp (MIL) . . . . . . . . . . . . . . . . . . . . 6E2-4
Intermittent "Check Engine"
Malfunction Indicator Lamp (MIL) . . 6E2-4
Reading Diagnostic
Trouble Codes . . . 6E2-5
Clearing
Trouble Codes . . . . . . . . . . . . 6E2-5
Diagnostic Test
Mode .............. 6E2-5
Engine Control
Module Learning
Ability . . . . . . . . . . . . . . . . . . . . . . . . 6E2-6
Field
Service Mode . . . . . . . . . . . . . . . . 6E2-6
Standard Nomenclature
for Certain
Electrical/Electronic
Components
and Systems . . . . . . . . . . . . . . . . . . . 6E2-6
Abbreviations and Glossary of Terms ..... 6E2-11
Driveability and Emissions
Section Summary ................... 6E2-12
Section .,. A"
Diagnostic Procedure Summary ...... 6E2-13
Data Link Connector
"SCAN Tools" ..... 6E2-14
Data
List (FO) ...................... 6E2-14
"SCAN Tool" Limitations and Use ...... 6E2-14
Intermittent Conditions ............ 6E2-14
"SCAN Tool" Positions ............... 6E2-14
Injector Pulse Width ............... 6E2-14
Closed Loop/Open Loop . . . . . . . . . . . .
6E2-14
Trouble Codes ................... 6E2-14
Throttle Position (TP) Sensor . . . . . . . . 6E2-14
Throttle Angle . . . . . . . . . . . . . . . . . . . 6E2-15 Heated
Oxygen
Sensor (H02S)
Vehicle Speed Sensor (VSS) ....... .
Programmable Read Only Memory ID .
Revolution
Per Minute (RPM) ...... .
Mile Per Hour (MPH) ............. .
Engine
Coolant Temperature (ECT) .. .
Intake Air Temperature (IAT)
Sensor
...................... .
Manifold Absolute Pressure (MAP) .. .
Barometric Pressure (BARO) ....... .
Exhaust Gas Recirculation
(EGR)
(ON/OFF) .................... .
Short Term (S.T.) Fuel Trim and
Long Term
(LT.) Fuel Trim ...... .
Long Term
(LT.) Fuel Trim ........ .
Idle Air Control (lAC) Counts ....... .
Desired Revolution
Per Minute ..... .
Air Conditioning (A/C) Request ..... .
Air Conditioning (A/C) Clutch ...... .
Power Steering Pressure (PSP)
Switch ...................... .
Battery Positive Voltage .......... .
Spark Advance .................. .
Start Up Engine Coolant .......... .
Engine
Speed (RPM) ............. .
Fuel Trim Enable ................ .
Air/Fuel Ratio .................. .
Induction Air Control ............. .
Section B -Driveability Symptoms ... .
Section C -Component Systems .... .
Engine
Control Module (ECM)
and
Sensors .................. .
Fuel Control System ............. .
Electric
Fuel Pump (in-tank) ....... .
Evaporative Emission
(EVAP)
Control System ................ .
Ignition Control (IC) .............. .
Exhaust Gas Recirculator
(EGR) .... .
Air Conditioning (A/C) Clutch Control .
Positive Crankcase Ventilation (PCV) .
Tools Needed
to Service the System .... .
General Specifications
............... .
Vacuum Hose Routing Diagram
........ .
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-15
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-16
6E2-17
6E2-17
6E2-17
6E2-17
6E2-17
6E2-17
6E2-17
6E2-17
6E2-18
6E2-21
6E2-22
~
... ...
•

---
DRIVEABILITV AND EMISSIONS 6E2-3
ALL NEW ISUZU VEHICLES ARE CERTIFIED BY THE UNITED STATES ENVIRONMENTAL PROTECTION
AGENCY AS CONFORMING TO THE REQUIREMENTS OF THE REGULATIONS FOR THE CONTROL OF AIR
POLLUTION FROM NEW MOTOR VEHICLES. THIS CERTIFICATION IS CONTINGENT ON CERTAIN
ADJUSTMENTS BEING SET TO FACTORY STANDARDS. IN MOST CASES, THESE ADJUSTMENT POINTS
EITHER HAVE BEEN PERMANENTLY SEALED AND/OR MADE INACCESSIBLE TO PREVENT INDISCRIMINATE
OR ROUTINE ADJUSTMENT IN THE FIELD. FOR THIS REASON, THE FACTORY PROCEDURE FOR
TEMPORARILY REMOVING PLUGS, CAPS, ETC., FOR PURPOSES OF SERVICING THE PRODUCT, MUST BE
STRICTLY FOLLOWED AND, WHEREVER PRACTICABLE, RETURNED TO THE ORIGINAL INTENT OF THE
DESIGN.
GENERAL INFORMATION
DRIVEABILITY
The driveability diagnosis procedures apply to various
systems in current
ISUZU vehicles. The procedures
assume
that the vehicle is worked on properly at one
time and the
problem is due to time, wear, dirt or other
causes.
Start with the introduction that follows. This
will describe a systematic diagnostic procedure.
Any system disconnected during diagnosis should be
reconnected. This
includes wires, hoses, linkage, etc.
EMISSIONS
The exhaust emission control systems used on
ISUZU engines perform a specific function to lower
exhaust emissions while maintaining good fuel
economy and driveability.
MAINTENANCE SCHEDULE
Refer to the Maintenance Schedule in Section "OB"
General Information for the maintenance service that
should be performed to retain emission control
performance.
INTRODUCTION
ELECTRONIC ENGINE CONTROL
All engines have an Engine Control Module (ECM)
to control the fuel system. The ECM varies the air/
fuel ratio by controlling the fuel flow through the
injectors.
In addition, the ECM controls the ignition timing,
fuel pump, and various other systems.
It is important to review the component sections
and
wiring diagrams in this Section for specific
components
controlled by the ECM and what
systems are non-ECM controlled.
WHAT THIS SECTION CONTAINS
Each ISUZU engine has system controls to reduce
exhaust emissions
while maintaining good
driveability and fuel economy. •
This Section explains:
•
How to use the Driveability and Emission
Section
"6E2" engines.
• A brief description of systems used to
control fuel and emissions.
• Abbreviations that are used in Driveability
and Emissions.
• Special tools used to diagnosis and repair a
system.
Before checking the
system, adhere to the
following information:
BLOCKING DRIVE WHEELS
The vehicle drive wheels should always be
blocked, and parking brake firmly set, while
checking the system.
VISUAL/PHYSICAL UNDERHOOD
INSPECTION
A careful visual and physical underhood
inspection must
be performed as part of any
diagnostic procedure
or in finding the cause of an
emissions test failure. This can often lead to fixing
a
problem without further steps. Inspect all
vacuum hoses for correct routing, pinches, cuts,
or disconnections. Be sure to inspect hoses that
are
difficult to see beneath the throttle body and
common chamber.
Inspect all the wires in the
engine
compartment for correct and good
connections, burned or chaffed spots, pinched
wires, or contact with sharp edges or hot exhaust
manifolds. This visual/physical inspection is very
important. It must be done carefully and
thoroughly.

6E2-4 DRIVEABILITY AND EMISSIONS
BASIC KNOWLEDGE REQUIRED
Before using this section of the Service Manual,
there are some areas that you should be familiar
with. Without this basic knowledge, you will have
trouble using the diagnostic procedures
contained in this section.
BASIC ELECTRIC CIRCUITS
You should understand the basic theory of
electricity, and know the meaning of voltage,
amps, and ohms. You should understand what
happens in a circuit with an open or a shorted
wire. You
should be able to read and understand a
wiring diagram. A shortto ground is referred to as
a ground to distinguish it from a short between
wires.
USE OF CIRCUIT TESTING TOOLS
You should know how to use a test light, how to
connect and use a tachometer, and
how to use
jumper wires to by-pass components to test
circuits. Care
should be taken to not deform the
terminal when testing.
USE OF DIGITAL VOLT-OHM METER
(DVOM)
You should be familiar with the Digital Volt-Ohm
Meter, particularly special tool J-39200 or
equivalent. You should be able to measure
voltage, resistance, and current and know how to
use the meter correctly.
The
Digital Volt-Ohm Meter is covered in the
"Special Tools" portion of this section.
DIAGNOSTIC INFORMATION
The diagnostic "Trouble Tree" charts and func­
tional checks in this manual are designed to locate
a faulty circuit or component through logic based
on the process
of elimination. The charts are
prepared
with the requirement that the vehicle
functioned correctly at the time of assembly and
that there are no multiple failures.
The Engine Control Module (ECM) performs a
continual self-diagnosis on certain control
functions. This diagnostic capability is
complemented by the diagnostic procedures
contained in this
manual. The ECM's language for
communicating the source of a malfunction is a
system
of Diagnostic Trouble Codes (DTCs). The
DTC(s) are
two or three digit numbers that can
range from12 to
51. When a malfunction is
detected by the ECM, a DTC is set and the
Malfunction Indicator Lamp is illuminated.
"CHECK ENGINE" MALFUNCTION
INDICATOR
LAMP (MIL)
This light is on the instrument panel and has two
functions:
• It is used to tell the driver that a problem has
occurred, and that the
vehicle should be
taken
for service as soon as reasonably
possible.
• It
is used by the technician to read out
'Trouble Codes" to help diagnose system
problems.
As a bulb and system check, the light will come
"ON" with the key "ON" and the engine not
running. When the engine is started, the light will
turn off. If the light remains on, the self-diagnostic
system has detected a
problem. If the problem
goes away, the light will go out in most cases after
10 seconds, but a Trouble Code will remain stored
in the
ECM.
When the light remains "ON" while the engine is
running,
or when a malfunction is suspected due
to a
driveability or emissions problem, a on-board
diagnostic system check
must be performed. The
procedures
for these checks are given in Section
"A". These checks will expose malfunctions
which may
not be detected if other diagnostics
are performed
prematurely.
INTERMITTENT "CHECK ENGINE"
MALFUNCTION INDICATOR
LAMP (MIL)
In the case of an "intermittent" problem, the
"Check Engine"
malfunction indicator lamp will
light
for ten (1 0) seconds and then will go out.
However, the corresponding
trouble code will be
stored in the
memory of the ECM until the battery
positive
voltage to the ECM has been removed.
When unexpected DTC(s) appear during the
DTC
code reading process, one can assume that these
DTC(s) were set by an intermittent malfunction
and could be helpful in diagnosing the system.
An intermittent
DTC may or may not re-set. If it is
an intermittent failure, a DTC Chart is not used.
Consult the "Diagnostic Aids" on the intermittent
trouble code. Section "B" also covers the topic of
"intermittents". A physical inspection of the
applicable sub-system most often will resolve the
problem.
II