check engine MITSUBISHI TRITON 1997 Workshop Manual

GENERAL ± How to Use This Manual00-2
HOW TO USE THIS MANUAL00100010210
SCOPE OF MAINTENANCE, REPAIR
AND SERVICING EXPLANATIONS
This manual provides explanations, etc. concerning
procedures for the inspection, maintenance, repair
and servicing of the subject model. Note, however,
that for engine and transmission-related component
parts, this manual covers only on-vehicle
inspections, adjustments, and the removal and
installation procedures for major components.
For detailed information concerning the inspection,
checking, adjustment, disassembly and reassembly
of the engine, transmission and major components
after they have been removed from the vehicle,
please refer to separate manuals covering the
engine and the transmission.
ON-VEHICLE SERVICE
ªOn-vehicle Serviceº is procedures for performing
inspections and adjustments of particularly
important locations with regard to the construction
and for maintenance and servicing, but other
inspection (for looseness, play, cracking, damage,
etc.) must also be performed.
INSPECTION
Under this title are presented inspection and
checking procedures to be performed by using
special tools and measuring instruments and by
feeling, but, for actual maintenance and servicing
procedures, visual inspections should always be
performed as well.
DEFINITION OF TERMS
STANDARD VALUE
Indicates the value used as the standard for judging
the quality of a part or assembly on inspection
or the value to which the part or assembly is
corrected and adjusted. It is given by tolerance.
LIMIT
Shows the standard for judging the quality of a
part or assembly on inspection and means the
maximum or minimum value within which the part
or assembly must be kept functionally or in strength.
It is a value established outside the range of
standard value.
REFERENCE VALUE
Indicates the adjustment value prior to starting the
work (presented in order to facilitate assembly and
adjustment procedures, and so they can be
completed in a shorter time).
CAUTION
Indicates the presentation of information particularly
vital to the worker during the performance of
maintenance and servicing procedures in order to
avoid the possibility of injury to the worker, or
damage to component parts, or a reduction of
component or vehicle function or performance, etc.
INDICATION OF TIGHTENING TORQUE
The tightening torque shown in this manual is a
basic value with a tolerance of +10% except the
following cases when the upper and lower limits
of tightening torque are given.
(1) The tolerance of the basic value is within +10%.
(2) Special bolts or the like are in use.
(3) Special tightening methods are used.

11A-2
ENGINE <4G6>
CONTENTS11109000399
GENERAL INFORMATION 3. . . . . . . . . . . . . . . . . .
SERVICE SPECIFICATIONS 3. . . . . . . . . . . . . . . . .
SEALANT 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 5. . . . . . . . . . . . . . . . . . . . . . . . . . .
ON-VEHICLE SERVICE 7. . . . . . . . . . . . . . . . . . . . .
Drive Belt Tension Check and Adjustment 7. . . . .
Ignition Timing Check and Adjustment 10. . . . . . .
Idle Speed Check 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Idle Mixture Check 11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Compression Pressure Check 12. . . . . . . . . . . . . . . .
Manifold Vacuum Check 13. . . . . . . . . . . . . . . . . . . . . Lash Adjuster Check 14. . . . . . . . . . . . . . . . . . . . . . . .
CAMSHAFT OIL SEAL 16. . . . . . . . . . . . . . . . . . . .
OIL PAN, OIL SCREEN 19. . . . . . . . . . . . . . . . . . . .
CYLINDER HEAD GASKET 21. . . . . . . . . . . . . . . .
TIMING BELT, TIMING BELT B 26. . . . . . . . . . . .
CRANKSHAFT FRONT OIL SEAL 32. . . . . . . . . .
CRANKSHAFT REAR OIL SEAL 35. . . . . . . . . . .
ENGINE ASSEMBLY 37. . . . . . . . . . . . . . . . . . . . . .

ENGINE <4G6> ± General Information/Service Specifications11A-3
GENERAL INFORMATION11100010322
Items4G634G64
Total displacement m
1,9972,351
Bore y Stroke mm85.0 x 88.086.5 x 100.0
Compression ratio9.59.5
Combustion chamberPentroof typePentroof type
Camshaft arrangementSOHCSOHC
Number of valve
Intake88
Number of valve
Exhaust88
Intake
OpeningBTDC 11
BTDC 18

Valve timing
Intake
ClosingABDC 53
ABDC 58

Valve timing
Exhaust
OpeningBBDC 63
BBDC 58

Exhaust
ClosingATDC 21
ATDC 18

Fuel system
Electronic control
multipoint fuel
injectionElectronic control
multipoint fuel
injection
Rocker armRoller typeRoller type
Auto-lash adjusterEquippedEquipped
SERVICE SPECIFICATIONS11100030342
ItemsStandard valueLimit
Alternator drive
belt
Tension NWhen checked294 ± 490±
belt
tension
When a used belt is installed343 ± 441±
When a new belt is installed490 ± 686±
Deflection
(Reference
When checked7.0 ± 9.0±
(Reference
value) mmWhen a used belt is installed7.5 ± 8.5±
When a new belt is installed5.5 ± 7.5±
Power steering
oilpumpdrive
Tension NWhen checked294 ± 490±
oil um drive
belt tensionWhen a used belt is installed343 ± 441±
When a new belt is installed490 ± 686±
Deflection
(Reference
When checked5.5 ± 7.5±
(Reference
value) mmWhen a used belt is installed6.0 ± 7.0±
When a new belt is installed4.0 ± 6.0±

ENGINE <4G6> ± Service Specifications11A-4
ItemsLimit Standard value
A/C compres-
sor drive belt
Tension NWhen checked355 ± 445±
sor drive belt
tensionWhen a used belt is installed355 ± 445±
When a new belt is installed530 ± 620±
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±
Basic ignition timing5
BTDC+2
±
Idle speed r/min750+100±
CO contents %0.5 or less±
HC contents ppm100 or less±
Compression pressure
(250±400 r/min) kPa
4G631,270min. 960
(250±400 r/min) kPa
4G641,320min. 1,000
Compression pressure difference of all cylinder kPa±max. 100
Intake manifold vacuum kPamin. 60±
Cylinder head bolt shank length mm±99.4
Auto-tensioner push rod movement mmWithin 1.0±
Timing belt tension torque Nm (Reference value)3.5±
Auto tensioner rod protrusion mm2.5 ± 3.0±

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 ± General Information13A-3
MULTIPOINT FUEL INJECTION (MPI)13100010265
GENERAL INFORMATION
The Multipoint Fuel Injection System consists
of sensors which detect the engine conditions,
the engine-ECU which controls the system
based on signals from these sensors, and
actuators which operate under the control of
the engine-ECU. The engine-ECU carries outactivities such as fuel injection control, idle
speed control and ignition timing control. In
addition, the engine-ECU is equipped with
several diagnosis modes which simplify
troubleshooting when a problem develops.
FUEL INJECTION CONTROL
The injector drive times and injector timing are
controlled so that the optimum air/fuel mixture
is supplied to the engine to correspond to the
continually-changing engine operation condi-
tions.
A single injector is mounted at the intake port
of each cylinder. Fuel is sent under pressure
from the fuel tank by the fuel pump, with the
pressure being regulated by the fuel pressure
regulator. The fuel thus regulated is distributed
to each of the injectors.
Fuel injection is normally carried out once for
each 2-cylinder group for every two rotationsof the crankshaft. This is called group fuel
injection. The engine-ECU provides a richer
air/fuel mixture by carrying out ªopen-loopº
control when the engine is cold or operating
under high load conditions in order to maintain
engine performance. In addition, when the
engine is warm or operating under normal
conditions, the engine-ECU controls the air/fuel
mixture by using the oxygen sensor signal to
carry out ªclosed-loopº control in order to obtain
the theoretical air/fuel mixture ratio that
provides the maximum cleaning performance
from the three way catalyst.
IDLE AIR CONTROL
The idle speed is kept at the optimum speed
by controlling the amount of air that bypasses
the throttle valve in accordance with changes
in idling conditions and engine load during
idling. The engine-ECU drives the idle speed
control (ISC) motor to keep the engine running
at the pre-set idle target speed in accordance
with the engine coolant temperature and airconditioner load. In addition, when the air
conditioner switch is turned off and on while
the engine is idling, the ISC motor operates
to adjust the throttle valve bypass air amount
in accordance with the engine load conditions
in order to avoid fluctuations in the engine
speed.
IGNITION TIMING CONTROL
The power transistor located in the ignition
primary circuit turns ON and OFF to control
the primary current flow to the ignition coil. This
controls the ignition timing in order to provide
the optimum ignition timing with respect to theengine operating conditions. The ignition timing
is determined by the engine-ECU from the
engine speed, intake air volume, engine coolant
temperature and atmospheric pressure.
SELF-DIAGNOSIS FUNCTION

When an abnormality is detected in one
of the sensors or actuators related to
emission control, the engine warning lamp
(check engine lamp) illuminates as a
warning to the driver.

When an abnormality is detected in one
of the sensors or actuators, a diagnosiscode corresponding to the abnormality is
output.

The RAM data inside the ENGINE-ECU
that is related to the sensors and actuators
can be read by means of the MUT-II. In
addition, the actuators can be force-driven
under certain circumstances.

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.