service MITSUBISHI TRITON 1997 User Guide

ENGINE <4G6> ± On-vehicle Service11A-11
16. Attach a sealing tape to the fixing bolt and nut only for
vehicles for Switzerland.
NOTE
Sealing tape is attached to all new vehicles.
IDLE SPEED CHECK11100190330
1. Before inspection, set the vehicle to the pre-inspection
condition.
2. Check the basic ignition timing. Adjust if necessary.
Standard value: 5 BTDC+2
3. After turning the ignition switch to OFF, connect the MUT-II
to the diagnosis connector.
4. Start the engine and run it at idle.
5. Run the engine at idle for 2 minutes.
6. Check the idle speed.
Curb idle speed: 750+100 r/min
NOTE
The idle speed is controlled automatically by the idle speed
control (ISC) system.
7. If the idle speed is outside the standard value, inspect
the MPI components by referring to GROUP 13A ±
Troubleshooting.
IDLE MIXTURE CHECK11100210265
1. Before inspection, set the vehicle to the pre-inspection
condition.
2. Check that the basic ignition timing is within the standard
value.
Standard value: 5 BTDC+2
3. Turn the ignition switch to OFF and connect the MUT-II
to the diagnosis connector.
4. Start the engine and run it at 2,500 r/min for 2 minutes.
5. Set the CO, HC tester.
6. Check the CO contents and the HC contents at idle.
Standard value:
CO contents: 0.5% or less
HC contents: 100 ppm or less
7. If there is a deviation from the standard value, check
the following items:

Diagnosis output

Closed-loop control (When the closed-loop control
is normal, the output signal of the oxygen sensor
changes between 0 ± 400 mV and 600 ± 1,000 mV
at idle.)

ENGINE <4G6> ± Engine Assembly11A-39
REMOVAL SERVICE POINTS
A
POWER STEERING OIL PUMP ASSEMBLY AND
A/C COMPRESSOR ASSEMBLY REMOVAL
1. Remove the oil pump and A/C compressor (with the hose
attached).
2. Suspend the removed oil pump (by using wire or similar
material) at a place where no damage will be caused
during removal/installation of the engine assembly.
B
ENGINE ASSEMBLY REMOVAL
1. Check that all cables, hoses, harness connectors, etc.
are disconnected from the engine.
2. Lift the chain block slowly to remove the engine assembly
upward from the engine compartment.
INSTALLATION SERVICE POINT

AENGINE ASSEMBLY INSTALLATION
Install the engine assembly. When doing so, check carefully
that all pipes and hoses are connected, and that none are
twisted, damaged, etc.

ENGINE <4D5> ± Service Specifications/Sealants11B-3
SERVICE SPECIFICATIONS11100030359
ItemsStandard valueLimit
Alternator drive belt
tension (for each
Tension NWhen checked245 ± 441±
tension (for each
belt)When a used belt is installed294 ± 392±)
When a new belt is installed392 ± 588±
Deflection
(Reference
When checked12.0 ± 17.0±
(Reference
value) mmWhen a used belt is installed13.0 ± 16.0±)
When a new belt is installed10.0 ± 13.0±
Power steering oil
pump drive belt ten
Tension NWhen checked294 ± 490±
pump drive belt ten-
sionWhen a used belt is installed343 ± 441±
When a new belt is installed490 ± 686±
Deflection
(Reference
When checked8.0 ± 12.0±
(Reference
value) mmWhen a used belt is installed9.0 ± 11.5±)
When a new belt is installed6.0 ± 8.0±
A/C compressor
drive
Tension NWhen checked320 ± 400±
drive
belt tensionWhen a used belt is installed320 ± 400±
When a new belt is installed480 ± 560±
Deflection
(Reference
When checked6.0 ± 7.0±
(Reference
value) mmWhen a used belt is installed6.0 ± 7.0±)
When a new belt is installed4.5 ± 5.5±
Valve clearance (at hot) mm0.25±
Injection timing (Value indicated on dial gauge mm)9
ATDC (1 + 0.03)±
Idle speed r/min750 + 100±
Idle up engine speed for ABS r/min1,900 + 100±
Compression pressure kPa3,040Min. 2,200
Compression pressure difference of all cylinder (at engine speed of 280
r/min) kPa±Max. 300
Timing belt tension mm4 ± 5±
Timing belt B tension mm4 ± 5±
SEALANTS11100050270
ItemsSpecified sealantRemarks
Oil panMITSUBISHI GENUINE PART
MD970389 or equivalentSemi-drying sealant
Semi-circular packing and rocker
cover seal, and cylinder head seal3M ATD Part No. 8660 or equivalent

ENGINE <4D5> ± Engine Assembly11B-35
REMOVAL SERVICE POINTS
A
POWER STEERING OIL PUMP ASSEMBLY AND
A/C COMPRESSOR ASSEMBLY REMOVAL
1. Remove the oil pump and A/C compressor (with the hose
attached).
2. Suspend the removed oil pump (by using wire or similar
material) at a place where no damage will be caused
during removal/installation of the engine assembly.
B
ENGINE ASSEMBLY REMOVAL
1. Check that all cables, hoses, harness connectors, etc.
are disconnected from the engine.
2. Lift the chain block slowly to remove the engine assembly
upward from the engine compartment.
INSTALLATION SERVICE POINT

AENGINE ASSEMBLY INSTALLATION
Install the engine assembly. When doing so, check carefully
that all pipes and hoses are connected, and that none are
twisted, damaged, etc.

MPI ± Service Specifications/Sealant13A-6
SERVICE SPECIFICATIONS13100030216
ItemsSpecifications
Basic idle speed r/min750+50
Idle speed when A/C is ON r/min900 at neutral position
Throttle position sensor adjusting voltage mV400 ± 1,000
Throttle position sensor resistance kW3.5 ± 6.5
Idle speed control servo coil resistance W28 ± 33 (at 20
C)
Intake air temperature sensor
resistance kW
20
C2.3 ± 3.0
resistance kW
80
C0.30 ± 0.42
Engine coolant temperature
sensor resistance kW
20
C2.1 ± 2.7
sensor resistance kW
80
C0.26 ± 0.36
Oxygen sensor output voltage V0.6 ± 1.0
Fuel pressure kPaVacuum hose disconnection324 ± 343 at curb idle
Vacuum hose connectionApprox. 265 at curb idle
Injector coil resistance W13 ± 16 (at 20
C)
SEALANT13100050038
ItemSpecified sealantRemark
Engine coolant temperature sensor
threaded portion3M Nut Locking Part No. 4171 or equivalentDrying sealant

MPI ± Troubleshooting13A-9
Engine warning lamp inspection items
Engine-ECU
Oxygen sensor
Air flow sensor
Intake air temperature sensor
Throttle position sensor
Engine coolant temperature sensor
Crank angle sensor
Top dead centre sensor
Barometric pressure sensor
Ignition timing adjustment signal
Injector
Immobilizer system
Caution
Engine warning lamp will come on even when terminal
for ignition timing adjustment is short-circuited.
Therefore, it is not abnormal that the lamp comes
on even when terminal for ignition timing adjustment
is short-circuited at the time of ignition timing
adjustment.
METHOD OF READING AND ERASING DIAGNOSIS
CODES
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.
INSPECTION USING MUT-II DATA LIST AND
ACTUATOR TESTING
1. Carry out inspection by means of the data list and the
actuator test function.
If there is an abnormality, check and repair the chassis
harnesses and components.
2. After repairing, re-check using the MUT-II and check that
the abnormal input and output have returned to normal
as a result of the repairs.
3. Erase the diagnosis code memory.
4. Remove the MUT-II.
5. Start the engine again and carry out a road test to confirm
that the problem has disappeared.

MPI ± Troubleshooting13A-26
INSPECTION PROCEDURE 5
No initial combustion (starting impossible)
Probable cause
In cases such as the above, the cause is probably that a spark plug is defective,
or that the supply of fuel to the combustion chamber is defective.
In addition, foreign materials (water, kerosene, etc.) may be mixed with the fuel.
Malfunction of the ignition system

Malfunction of the fuel pump system

Malfunction of the injectors

Malfunction of the engine-ECU

Malfunction of the immobilizer system with immobilizer system>

Foreign materials in fuel
Check battery voltage when cranking.
OK:8 V or higherNGCheck the battery. (Refer to GROUP 54 ± Battery.)
OK
Is immobilizer-ECU diagnosis code displayed? immobilizer system>Ye sCheck the immobilizer.
(Refer to GROUP 54 ± Ignition Key and Immobilizer.)
No
MUT-II: Inspection of no initial combustion.
(Refer to P.13A-47, INSPECTION PROCEDURE 34.)
OK
Can any sound be heard from the injectors when cranking?NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
Ignition system: Inspection of no initial combustion.
(Refer to P.13A-47, INSPECTION PROCEDURE 35.)
OK
Check the following items.

Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 ± On-vehicle service.)

Check if the injectors are clogged.

Check if foreign materials (water, alcohol, etc.) got into fuel.

Check the compression pressure.

Check the immobilizer system. (Refer to GROUP 54 ± Ignition Key and Immobilizer.)

MPI ± Troubleshooting13A-27
INSPECTION PROCEDURE 6
Initial combustion but no complete combustion
(starting impossible)
Probable cause
In such cases as the above, the cause is probably that the spark plugs are generating
sparks but the sparks are weak, or the initial mixture for starting is not appropriate.
Malfunction of the ignition system

Malfunction of the injector system

Foreign materials in fuel

Poor compression

Malfunction of the engine-ECU
Check battery voltage when cranking.
OK:8 V or higherNGCheck the battery. (Refer to GROUP 54 ± Battery.)
OK
MUT-II: Check if uncompleted combustion occurs.
(Refer to P.13A-48, INSPECTION PROCEDURE 36.)
OK
Can any sound be heard from the injectors when cranking?NGCheck the injector system, (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
Is starting good if the engine is cranked with the accelerator pedal
slightly depressed?Ye sCheck ISC servo for op-
eration sound.
(Refer to P.13A-90.)NGCheck the ISC servo sys-
tem. (Refer to P.13A-45,
INSPECTION PROCE-
DURE 31.)
OK

Clean the throttle valve area. (Refer to P.13A-78.)

Check and adjust the fixed SAS. (Refer to P.13A-79.)
No
Check the ignition timing when cranking.
OK:Approx. 5BTDCNGCheck that the distributor is installed properly.
OK
Check the following items.

Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 ± On-vehicle Service.)

Check if the injectors are clogged.

Check the compression pressure. (Refer to GROUP 11 ± On-vehicle Service.)

Check fuel lines for clogging.

Check if foreign materials (water, alcohol, etc.) got into fuel.

MPI ± Troubleshooting13A-28
INSPECTION PROCEDURE 7
In takes too long time to start. (Incorrect starting)
Probable cause
In cases such as the above, the cause is probably that the spark is weak and ignition
is difficult, the initial mixture for starting is not appropriate, or sufficient compression
pressure is not being obtained.
Malfunction of the ignition system

Malfunction of the injector system

Inappropriate gasoline use

Poor compression
Check battery voltage when cranking
OK:8 V or higherNGCheck the battery. (Refer to GROUP 54 ± Battery.)
OK
MUT-II: Check if uncomplete combustion occurs.
(Refer to P.13A-48, INSPECTION PROCEDURE 36.)
OK
Can any sound be heard from the injectors when cranking?NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
Check the ignition timing when cranking.
OK:Approx. 5BTDCNGCheck that the distributor is installed properly.
OK
Check the following items.

Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 ± On-vehicle Service.)

Check if the injectors are clogged.

Check the compression pressure. (Refer to GROUP 11 ± On-vehicle Service.)

Check if foreign materials (water, alcohol, etc.) got into fuel.

MPI ± Troubleshooting13A-29
INSPECTION PROCEDURE 8
Unstable idling (Rough idling, hunting)
Probable cause
In cases as the above, the cause is probably that the ignition system, air/fuel mixture,
idle speed control (ISC) or compression pressure is defective.
Because the range of possible causes is broad, inspection is narrowed down to simple
items.
Malfunction of the ignition system

Malfunction of air-fuel ratio control system

Malfunction of the ISC system

Malfunction of the purge control solenoid valve system

Malfunction of the EGR solenoid valve system

Poor compression

Drawing air into exhaust system
Were the battery terminals disconnected?Ye sAfter warming-up, let the engine run at idling for 10 minutes.
No
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
No
Does idling speed fluctuate excessively?Ye sCheck if hunting occurs.
(Refer to P.13A-48, INSPECTION PROCEDURE 37.)
No
Check the ISC servo for operation sound. (Refer to P.13A-90.)NGCheck the ISC servo system.
(Refer to P.13A-45, INSPECTION PROCEDURE 31.)
OK
Check the injector for operation sound.NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
MUT-II: Check if idling speed is unstable.
(Refer to P.13A-49, INSPECTION PROCEDURE 38.)
OK
Check the ignition timing.
(Refer to GROUP 11 ± On-vehicle Service.)NGCheck that the distributor is installed properly.
OK
Check the following items.

Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 ± On-vehicle Service.)

Check the purge control system. (Refer to GROUP 17 ± Emission Control System.)

Check the EGR control system. (Refer to GROUP 17 ± Emission Control System.)

Check the compression pressure. (Refer to GROUP 11 ± On-vehicle Service.)

Check if foreign materials (water, alcohol, etc.) got into fuel.