1997 MITSUBISHI TRITON check engine
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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.
Page 216 of 1310
MPI ± Injector13A-93
REMOVAL SERVICE POINT
ADELIVERY 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)
Page 245 of 1310
ENGINE COOLING ± Cooling Fan14-6
INSPECTION14100220023
COOLING FAN CHECK
Check blades for damage and cracks.
Check for cracks and damage around bolt holes in fan
hub.
If any portion of fan is damaged or cracked, replace cooling
fan.
FAN CLUTCH CHECK
Check to ensure that fluid in fan clutch is not leaking
at case joint and seals. If fluid quantity decreases due
to leakage, fan speed will decrease and engine
overheating might result.
When a fan attached to an engine is turned by hand,
it should give a sense of some resistance. If fan turns
lightly, it is faulty.
Check bimetal strip for damage.
Page 281 of 1310
ENGINE ELECTRICAL ± Charging System16-6
This test determines whether the alternator output
current is normal.
(1) Before the test, always be sure to check the
following.
Alternator installation
Battery (Refer to GROUP 54 ± Battery.)
NOTE
The battery should be slightly discharged.
The load needed by a fully-charged battery
is insufficient for an accurate test.
Alternator drive belt tension (Refer to
GROUP 11 ± On-vehicle Service.)
Fusible link
Abnormal noise from the alternator while
the engine is running.
(2) Turn the ignition switch off.
(3) Disconnect the negative battery cable.
(4) Disconnect the alternator output wire from the
alternator ªBº terminal. Connect a DC test
ammeter with a range of 0 ± 100 A in series
between the ªBº terminal and the disconnected
output wire. (Connect the (+) lead of the
ammeter to the ªBº terminal. Connect the (±)
lead of the ammeter to the disconnected output
wire.)
Caution
Never use clips but tighten bolts and nuts
to connect the line. Otherwise loose
connections (e.g. using clips) will lead to
a serious accident because of high current.
NOTE
An inductive-type ammeter which enables
measurements to be taken without
disconnecting the alternator output wire should
be recommended.
(5) Connect a voltmeter with a range of 0 ± 20 V
between the alternator ªBº terminal and the
earth. (Connect the (+) lead of the voltmeter
to the ªBº terminal, and then connect the (±)
lead of the voltmeter to the earth.)
(6) Connect the negative battery cable.
(7) Connect a tachometer. (Refer to GROUP 11
± On-vehicle Service.)
(8) Leave the hood open.
(9) Check that the reading on the voltmeter is equal
to the battery voltage.
NOTE
If the voltage is 0 V, the cause is probably
an open circuit in the wire or fusible link between
the alternator ªBº terminal and the battery (+)
terminal.(10)Turn the light switch on to turn on headlamps
and then start the engine.
(11) Immediately after setting the headlamps to high
beam and turning the heater blower switch to
the high revolution position, increase the engine
speed to 2,500 r/min and read the maximum
current output value displayed on the ammeter.
Limit: 70% of normal current output
NOTE
For the nominal current output, refer to the
Alternator Specifications.
Because the current from the battery will
soon drop after the engine is started, the
above step should be carried out as quickly
as possible in order to obtain the maximum
current output value.
The current output value will depend on
the electrical load and the temperature of
the alternator body.
If the electrical load is small while testing,
the specified level of current may not be
output even though the alternator is normal.
In such cases, increase the electrical load
by leaving the headlamps turned on for
some time to discharge the battery or by
using the lighting system in another vehicle,
and then test again.
The specified level of current also may not
be output if the temperature of the alternator
body or the ambient temperature is too
high. In such cases, cool the alternator and
then test again.
(12)The reading on the ammeter should be above
the limit value. If the reading is below the limit
value and the alternator output wire is normal,
remove the alternator from the engine and
check the alternator.
(13)Run the engine at idle after the test.
(14)Turn the ignition switch off.
(15)Remove the tachometer.
(16)Disconnect the negative battery cable.
(17)Disconnect the ammeter and voltmeter.
(18)Connect the alternator output wire to the
alternator ªBº terminal.
(19)Connect the negative battery cable.
Page 371 of 1310
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.
Page 372 of 1310
AUTOMATIC TRANSMISSION ± Troubleshooting23-5
D RANGE TEST
Correct
Carry out the TEST 1 again.
Ye s
Check the shifting points.IncorrectLine pressure malfunction
Governor malfunction
Incorrect throttle cable adjustment
Ye s
Does the upshift from 3-speed to 4-speed occur? (with throttle
valve opening under 85%)No3 ± 4 shift valve malfunction
Governor malfunction
Overdrive switch or overdrive solenoid malfunction
Overdrive control relay malfunction
Engine coolant temperature switch malfunction <4G6>
Ye s
Does the upshift from 2-speed to 3-speed occur?No2 ± 3 shift valve malfunction
Governor malfunction
NG
Does the upshift from 1-speed to 2-speed occur?No1 ± 2 shift valve malfunction
Governor malfunction
TEST 1
Start with throttle valve opened (50 % and full), and check upshift
from 1-speed 2-speed, 2-speed 3-speed and 3-speed
4-speed. Check that shifting points match shift pattern.OKTEST 2
Correct
Carry out TEST 2 again.
Ye s
Check the shifting point.IncorrectLine pressure malfunction
Governor malfunction
Detent regulator valve malfunction
NG
Does the downshift occur?NoShift valves malfunction
Governor malfunction
Overdrive switch or overdrive solenoid malfunction
Overdrive control relay malfunction
Detection switch malfunction
TEST 2
Kickdown traveling at 2-speed, 3-speed and 4-speed. Check that
possible kickdown vehicle speed limit at 2-speed 1-speed,
3-speed 1-speed, 3-speed 2-speed, or 4-speed 1-speed,
4-speed 2-speed, 4-speed 3-speed conforms with the shift
pattern.OKTEST 3
Correct
Carry out TEST 3 again.
Ye s
Check the Shifting point.IncorrectIncorrect throttle cable adjustment
Governor malfunction
Line pressure malfunction
Low coast modulator valve malfunction
NG
Does the downshift from 2-speed to 1-speed occur?No1 ± 2 shift valve malfunction
Governor malfunction
TEST 3
When traveling in 3-speed or 4-speed, release accelerator pedal
and shift to L. Check that 3-speed 2-speed or 4-speed 3-speed
takes place immediately and 2-speed 1-speed downshift con-
forms with shift pattern.OKTEST 4
Page 373 of 1310
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?NoLock 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?NoGovernor 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.)
Page 374 of 1310
AUTOMATIC TRANSMISSION ± Troubleshooting23-7
2 RANGE TEST
Correct
Carry out TEST 1 again.
Ye s
Check the shifting point.IncorrectMisadjusted throttle cable
Governor malfunction
Line pressure malfunction
No
Does the upshift from 1-speed to 2-speed occur?No1 ± 2 shift valve malfunction
Governor malfunction
TEST 1
Start with throttle valve opening at 50% and full. Does the shifting
points conform with the shift pattern when upshifting from 1-speed
2-speed?Ye sTEST 2
Ye s
Carry out TEST 2 again.
NG
Does the downshift occur and is the shifting point correct?NoDetent regulator valve malfunction
Governor malfunction
Misadjusted throttle cable
1 ± 2 shift valve malfunction
Line pressure malfunction
TEST 2
Kickdown and check that possible kickdown vehicle speed limit
at 2-speed 1-speed conforms with shift pattern.OKCarry out road test in L range.
L RANGE TEST
No
Carry out road test in R range.
TEST 1
Does the transmission upshift to 2-speed?Ye sLow coast modulator valve malfunction
Governor malfunction
Low line pressure
R RANGE TEST
Ye s
Carry out road test in P range.
TEST 1
Is the engine r/min by stall test correct?NoBrake No. 3 malfunction
Overdrive clutch or direct clutch malfunction
Overdrive one-way clutch malfunction
Low line pressure
P RANGE TEST
Ye s
End
TEST 1
Park vehicle on an incline (more than 5) and release parking
and service brakes. Does the vehicle move?NoPark mechanism malfunction
Misadjusted shift lever