oil pressure MITSUBISHI TRITON 1997 User Guide

MPI ± Troubleshooting13A-35
INSPECTION PROCEDURE 15
Hesitation, sag or stumble
Probable cause
In cases such as the above, the cause is probably that ignition system, air/fuel mixture
or compression pressure is defective.
Malfunction of the ignition system

Malfunction of air-fuel ratio control system

Malfunction of the fuel supply system

Malfunction of the EGR control solenoid valve system

Poor compression
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
No
Check the injectors for operation sound.NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
Check the ignition timing.
(Refer to GROUP 11 ± On-vehicle Service.)NGCheck that the distributor is installed properly.
OK
MUT-II: Check if hesitation, sag, stumble or poor acceleration occur.
(Refer to P.13A-51, INSPECTION PROCEDURE 40.)
OK
Check the fuel pressure. (Refer to P.13A-81.)
OK
Check the following items.

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

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

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

Check the fuel filter or fuel line for clogging.
INSPECTION PROCEDURE 16
The feeling of impact or vibration when accelerating
Probable cause
In cases such as the above, the cause is probably that there is an ignition leak
accompanying the increase in the spark plug demand voltage during acceleration.
Malfunction of the ignition system
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
No
Check the following items.

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

Check for occurrence of ignition leak.

MPI ± Troubleshooting13A-36
INSPECTION PROCEDURE 17
The feeling of impact or vibration when decelerating.
Probable cause
Malfunction of the ISC system is suspected.
Malfunction of the ISC system
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
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
MUT-II Data list
14 Throttle position sensor (Refer to P.13A-57.)NGCheck the throttle position sensor system. (Refer to P.13A-13, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK
MUT-II Data list
26 Idle position switch (Refer to P.13A-57.)NGCheck the idle position switch system.
(Refer to P.13A-40, INSPECTION PROCEDURE 25.)
OK
Clean the throttle valve area. (Refer to P.13A-78.)
INSPECTION PROCEDURE 18
Poor acceleration
Probable cause
Defective ignition system, abnormal air-fuel ratio, poor compression pressure, etc.
are suspected.
Malfunction of the ignition system

Malfunction of air-fuel ratio control system

Malfunction of the fuel supply system

Poor compression pressure

Clogged exhaust system
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
No
Check the injectors for operation sound.NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
Check the ignition timing.
(Refer to GROUP 11 ± On-vehicle Service.)NGCheck that the distributor is installed properly.
OK
MUT-II: Check if hesitation, sag, stumble or poor acceleration occur.
(Refer to P.13A-51, INSPECTION PROCEDURE 40.)
OK
Check the fuel pressure. (Refer to P.13A-81.)
OK
Check the following items.

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

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

Check the fuel filter or fuel line for clogging.

Broken air intake hose

Clogged air cleaner

MPI ± Troubleshooting13A-37
INSPECTION PROCEDURE 19
Surge
Probable cause
Defective ignition system, abnormal air-fuel ratio, etc. are suspected.
Malfunction of the ignition system

Malfunction of air-fuel ratio control system

Malfunction of the EGR control solenoid valve system
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
No
Check the injectors for operation sound.NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
Check the ignition timing.
(Refer to GROUP 11 ± On-vehicle Service.)NGCheck that the distributor is installed properly.
OK
MUT-II: Check if surge occurs.
(Refer to P.13-52, INSPECTION PROCEDURE 41.)
OK
Check the fuel pressure. (Refer to P.13A-81.)
OK
Check the following items.

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

Check the EGR control system. (Refer to GROUP 17 ± Emission Control System.)
INSPECTION PROCEDURE 20
Knocking
Probable cause
In cases as the above, the cause is probably that the heat value of the spark plug
is inappropriate.
Inappropriate heat value of the spark plug
Check the following items.

Spark plugs

Check if foreign materials (water, alcohol, etc.) got into fuel.
INSPECTION PROCEDURE 21
Dieseling
Probable cause
Fuel leakage from injectors is suspected.
Fuel leakage from injectors
Check the injectors for fuel leakage.

MPI ± Troubleshooting13A-38
INSPECTION PROCEDURE 22
Too high CO and HC concentration when idling
Probable cause
Abnormal air-fuel ratio is suspected.
Malfunction of the air-fuel ratio control system

Deteriorated catalyst
Check trouble symptom.
No
Check the ignition timing.
(Refer to GROUP 11 ± On-vehicle Service.)NGCheck that the distributor is installed properly.
OK
MUT-II Data list
21 Engine coolant temperature sensor. (Refer to P.13A-57.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13A-14, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
OK
MUT-II Data list
13 Intake air temperature sensor (Refer to P.13A-57.)NGCheck the intake air temperature sensor system. (Refer to P.13A-12,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 13.)
OK
MUT-II Data list
25 Barometric pressure sensor (Refer to P.13A-57.)NGCheck the barometric pressure sensor system. (Refer to P.13A-18,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 25.)
OK
MUT-II Data list
11 Oxygen sensor
OK:600 ± 1,000 mV when racing suddenly (Refer to P.13A-57.)NGCheck the oxygen sensor system. (Refer to P.13A-11, INSPECTION
PROCEDURE FOR DIAGNOSIS CODE 11.)
OK
MUT-II Data list
11 Oxygen sensor
OK:Repeat 0 ± 400 mV and 600 ± 1,000 mV alternately when
idling. (Refer to P.13A-57.)OK
NG
Check the fuel pressure. (Refer to P.13A-81.)
OK
NG
Check the following items.

Check the injectors for operation sound.

Check the injectors for fuel leakage.

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

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

Check the positive crankcase ventilation system. (Refer to GROUP 17 ± Emission Control System.)

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 trouble symptom.
NG
Replace the catalytic converter.
Replace the oxygen sensor.
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.

MPI ± On-vehicle Service13A-83
14. Stop the engine and check change of fuel pressure gauge
reading. Normal if the reading does not drop within 2
minutes. If it does, observe the rate of drop and
troubleshoot and repair according to the table below.
SymptomProbable causeRemedy
Fuel pressure drops gradually after
engine is stopped
Leaky injectorReplace injector
engine is sto ed
Leaky fuel regulator valve seatReplace fuel pressure regulator
Fuel pressure drops sharply
immediately after engine is stoppedCheck valve in fuel pump is held openReplace fuel pump
15. Release residual pressure from the fuel pipe line. (Refer
to P.13A-84.)
16. Remove the fuel pressure gauge and special tool from
the delivery pipe.
Caution
Cover the hose connection with rags to prevent splash
of fuel that could be caused by some residual pressure
in the fuel pipe line.
17. Replace the O-ring at the end of the fuel high pressure
hose with a new one. Furthermore, apply engine oil to
the new O-ring before replacement.
18. Fit the fuel high pressure hose over the delivery pipe
and tighten the bolt to specified torque.
Tightening torque: 5 Nm
19. Check for fuel leaks.
(1) Apply the battery voltage to the fuel pump drive
terminal to drive the fuel pump.
(2) Under fuel pressure, check the fuel line for leaks.

MPI ± Injector13A-93
REMOVAL SERVICE POINT
A
DELIVERY PIPE/INJECTOR REMOVAL
Remove the delivery pipe (with the injectors attached to it).
Caution
Care must be taken, when removing the delivery pipe,
not to drop the injector.
INSTALLATION SERVICE POINT

AINJECTOR/FUEL PRESSURE REGULATOR/
HIGH-PRESSURE FUEL HOSE INSTALLATION
(1) Apply a drop of new engine oil to the O-ring.
Caution
Be sure not to let engine oil in the delivery pipe.
(2) While turning the injector, high-pressure fuel hose and
fuel pressure regulator to the right and left, install the
delivery pipe, while being careful not to damage the O-ring.
After installing, check that the hose turns smoothly.
(3) If it does not turn smoothly, the O-ring may be trapped,
remove the fuel pressure regulator and then re-insert
it into the delivery pipe and check once again.
(4) Tighten the high-pressure fuel hose and fuel pressure
regulator to the specified torque.
Tightening torque:
9 Nm (Fuel pressure regulator)
5 Nm (High-pressure fuel hose)

ENGINE COOLING ±
General Information/
Service Specifications/Lubricant/Sealants14-2
GENERAL INFORMATION14100010125
The cooling system is designed to keep every part
of the engine at appropriate temperature in
whatever condition the engine may be operated.
The cooling method is of the water-cooled, pressure
forced circulation type in which the water pump
pressurizes coolant and circulates it throughout the
engine. If the coolant temperature exceeds the
prescribed temperature, the thermostat opens to
circulate the coolant through the radiator as well
so that the heat absorbed by the coolant may be
radiated into the air.The water pump is of the centrifugal type and is
driven by the drive belt from the crankshaft.
The radiator is the corrugated fin, down flow type.
ItemsSpecifications
RadiatorPerformance kJ/h4G63 114,700
4G63 126,800
4G64, 4D56 <2WD>170,000
4D56 <4WD>227,300
Automatic transmission oil coolerPerformance kJ/h4G63 6,400
4D56 6,300
SERVICE SPECIFICATIONS14100030121
ItemsStandard valueLimit
High pressure valve opening pressure of radiator cap kPa75 ± 10565
Range of coolant antifreeze concentration of radiator %30 ± 60±
ThermostatValve opening temperature of thermostat
C82 + 1.5±
Full-opening temperature of thermostat
C95±
Valve lift (at 95
C) mm4G6, 4D56 <4WD>8.5 or more±
4D56 <2WD>8 or more±
LUBRICANT14100040100
ItemsQuantity

HIGH QUALITY ETHYLENE GLYCOL ANTIFREEZE COOLANT4G637.4
4G64, 4D56 <2WD>7.7
4D56 <4WD>7.8
SEALANTS14100050110
ItemsSpecified sealantRemarks
Cylinder block drain plug3M Nut Locking Part No. 4171 or equivalentDrying sealant
Water by-pass fitting <4G6>Mitsubishi Genuine Parts No. MD970389 or
equivalentSemi-drying sealant

AUTOMATIC TRANSMISSION ±
General Information/
Service Specifications23-2
GENERAL INFORMATION23100010141
ItemsVehicles with 4G63 engineVehicles with 4D56 engine
Transmission modelR4AW2-6V4AW2-6
Type4-speed full automatic4-speed full automatic
Gear ratio1st2.8262.826
2nd1.4931.493
3rd1.0001.000
4th0.7300.688
Reverse2.7032.703
Transfer type±2-speed
Gear ratioHigh±1.000
Low±1.925
Speedometer gear ratio (driven/drive)22/625/8
SERVICE SPECIFICATIONS23100030130
ItemsStandard value
Distance between inner cable stopper and end of outer cable <4G63> mm0 ± 1
Distance between inner cable stopper and end of outer cable <4D56> mm34 ± 35
Lock-up solenoid valve coil resistance (at 20
C) WApprox. 13
Stall speed r/min4G632,100 ± 2,400
4D562,300 ± 2,600
Governor pressure kPa1,000 r/min137 ± 166
2,000 r/min245 ± 284
3,200 r/min402 ± 460
Line pressure kPaAt idle speedD range480 ± 558
R range735 ± 852
At stall speedD range1,019 ± 1,195
R range1,519 ± 1,911
Operation temperature of engine coolant
temperature switch
C
On (continuity)50 + 3
tem erature switch
C
Off (no continuity)43
Clearance between shift lever guide and steering column mm2.4 ± 3.6

AUTOMATIC TRANSMISSION ± Troubleshooting23-4
TROUBLESHOOTING23100760152
STANDARD FLOW OF DIAGNOSIS TROUBLESHOOTING
Automatic transmission malfunctions may be caused by the following conditions.
(1) Improper maintenance and adjustment
(2) Shift control system malfunction
(3) Mechanical malfunctions
(4) Hydraulic malfunctions
(5) Poor engine performance
Troubleshooting in the event of any such malfunctions should begin by checking fluid level, ATF condition,
manual linkage adjustment, throttle control cable adjustment and other conditions whose deviation from
standards can be readily known. Then, road test shall be performed to determine whether or not the
problem has been corrected or more diagnosis is necessary. If the problem still persists after these tests
and corrections, hydraulic tests should be performed for further troubleshooting.
Road test (guess what causes malfunc-
tion.)
Check how A/T works in each drive
range to find a defective system.
A/T control component inspection
Check the throttle cable, inhibitor switch,
overdrive switch, overdrive solenoid
valve, overdrive control relay, defective
switch, engine coolant temperature
switch and vehicle speed sensor.
Torque converter stall test (Inspection
of engine performance and mechanical
function)
Check the engine performance, torque
converter operation and clutch and
brake sliding performance.
Hydraulic pressure test (Inspection of
hydraulic control mechanism)
Measure the fluid line pressure and
check for malfunctions of the oil pump
or regulator valve and for oil leaks.
Oil leak inspection
Visually check gaskets and oil seals for
leaks.
Adjustment of basic inspection items
ROAD TEST 23100780158
Prior to performing road test, be sure to make basic checks including check and adjustment of fluid
level and condition and adjustment of the throttle cable. For road test, the transfer must be placed in
the 2H (2WD-high) position. In road test, various changes such as slips in transmission and shifting
conditions are checked and the transmission operation at each shift position must have been checked.

AUTOMATIC TRANSMISSION ± Troubleshooting23-6
Ye s
Carry out TEST 4 again.
Ye s
Does the engine brake function in L range?NoBrake No. 3 malfunction
No
Does the engine brake function in 2 range?NoBrake No. 1 malfunction
TEST 4
When traveling in 3-speed or 4-speed, shift to 2 and L. Does the
engine brake function in each range?Ye sTEST 5
Ye s

High line pressure

Accumulator malfunction

Check ball malfunctionCarry out TEST 5 again.
TEST 5
Is there abnormal noise(s) during acceleration and deceleration?
Is there shocks when slipping and changing speed?NoTEST 6
Ye s

Incorrect torque converter installation

Oil pump malfunction

Shifting gear not meshing correctly

Incorrect drive plate installationCarry out TEST 6 again.
TEST 6
Is there abnormal noise(s) or vibration when traveling in 3-speed
or 4-speed?NoTEST 7
NOTE
Abnormal noises and vibrations are often caused by an unbalanced propeller shaft, differential, tyre,
torque converter, engine, etc. Extremely thorough inspection is therefore required.
Ye s
Carry out TEST 7 again.
Ye s
Does lock up go on, off?No
Lock up signal valve malfunction

Lock up relay valve malfunction

Lock up clutch malfunction
No
Does the moment when lock up turns ON or OFF conform with
the shift pattern?No
Governor malfunction

Line pressure malfunction
TEST 7
Check that lock up ON, OFF. Does the shifting points conform
with shift pattern?Ye sCarry out the road test in 2 range.
NOTE
(1) Determine the moment when lock up turns ON by decreased engine r/min or by a slight shock back
and forth.
(2) Determine the moment when lock up turns OFF by increased engine r/min.
(3) Check lock up condition by pumping the accelerator slightly. If engine r/min rises in accordance with
throttle valve opening size, determine that the lock up is OFF, if not, determine it ON.
(When lock up is OFF, drive power is transferred through the fluid in the torque converter and therefore,
when the accelerator pedal is depressed, slipping occurs inside the torque converter with a resulting
large increase in engine r/min.)