1997 MITSUBISHI TRITON oil pressure

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 <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

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 ± 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-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.