fuel MITSUBISHI TRITON 1997 User Guide

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-10
FAIL-SAFE FUNCTION REFERENCE TABLE13100910190
When the main sensor malfunctions are detected by the diagnosis function, the vehicle is controlled
by means of the pre-set control logic to maintain safe conditions for driving.
Malfunctioning itemControl contents during malfunction
Air flow sensor1. Uses the throttle position sensor signal and engine speed signal (crank angle sensor
signal) to take reading of the basic injector drive time and basic ignition timing from
the pre-set mapping.
2. Fixes the ISC servo in the appointed position so idle control is not performed.
Intake air temperature
sensorControls as if the intake air temperature is 25
C.
Throttle position
sensor (TPS)No increase in fuel injection amount during acceleration due to the throttle position sensor
signal.
Engine coolant
temperature sensorControls as if the engine coolant temperature is 80
C.
Top dead centre
sensorInjects fuel to all cylinders simultaneously.
(However, after the ignition switch is turned to ON, the No. 1 cylinder top dead centre is not
detected at all.)
Barometric pressure
sensorControls as if the barometric pressure is 101 kPa.
Oxygen sensorAir/fuel ratio feedback control (closed loop control) is not performed.
INSPECTION CHART FOR DIAGNOSIS CODES13100870214
Code No.Diagnosis itemReference page
11Oxygen sensor system13A-11
12Air flow sensor system13A-12
13Intake air temperature sensor system13A-12
14Throttle position sensor system13A-13
21Engine coolant temperature sensor system13A-14
22Crank angle sensor system13A-15
23Top dead centre sensor system13A-16
24Vehicle speed sensor system13A-17
25Barometric pressure sensor system13A-18
36*Ignition timing adjustment signal system13A-19
41Injector system13A-19
54Immobilizer system13A-20
NOTE
*: Malfunction code No. 36 is not memorized.

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.

MPI ± Troubleshooting13A-32
INSPECTION PROCEDURE 11
When the engine is cold, it stalls at idling. (Die out)
Probable cause
In such cases as the above, the cause is probably that the air/fuel mixture is inappropriate
when the engine is cold, or that the intake air volume is insufficient.
Malfunction of the ISC servo system

Malfunction of the throttle body

Malfunction of the injector system

Malfunction of the ignition 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.
OK
Check the fuel pressure. (Refer to P.13A-81.)
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 compression pressure. (Refer to GROUP 11 ± On-vehicle Service.)

Check the engine oil viscosity.
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
Check the injector for operation sound.NGCheck the injector system. (Refer to P.13A-19, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
Ye s
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.)
No
Is engine-idling stable after the warming-up?NoCheck if the unstable idling (Rough idling, hunting).
(Refer to P.13A-29, INSPECTION PROCEDURE 8.)
No
Does the engine stall right after the accelerator pedal is released?Ye sClean the throttle valve
area. (Refer to P.13A-78.)Check and adjust the
fixed SAS.
(Refer to P.13A-79.)
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 Actuator test
10 EGR control solenoid valve (Refer to P.13A-62.)NGCheck the EGR control solenoid valve system. (Refer to P.13A-46,
INSPECTION PROCEDURE 33.)

MPI ± Troubleshooting13A-33
INSPECTION PROCEDURE 12
When the engine is hot, it stalls at idling. (Die out)
Probable cause
In such cases as the above, the cause is probably that ignition system, air/fuel mixture,
idle speed control (ISC) or compression pressure is defective.
In addition, if the engine suddenly stalls, the cause may also be a defective connector
contact.
Malfunction of the ignition system

Malfunction of air-fuel ratio control system

Malfunction of the ISC system

Drawing air into intake system

Improper connector contact
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
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
Does the engine stall right after the accelerator pedal is released?Ye sClean the throttle valve
area. (Refer to P.13A-78.)Check and adjust the
fixed SAS.
(Refer to P.13A-79.)
No
Does the engine stall easily again?NoWhile carrying out an intermittent malfunction simulation test (Refer
to GROUP 00 ± Points to Note for Intermittent Malfunctions.), check
for sudden changes in the signals shown below.

Crank angle sensor signal

Air flow sensor signal

Injector drive signal
Primary and secondary
ignition signal

Fuel pump drive signal

Engine-ECU power supply
voltage
Ye s
MUT-II: Engine stalling inspection when the engine is warm and
idling. (Refer to P.13A-50, INSPECTION PROCEDURE 39.)
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 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-34
INSPECTION PROCEDURE 13
The engine stalls when starting the car. (Pass out)
Probable cause
In cases such as the above, the cause is probably misfiring due to a weak spark,
or an inappropriate air/fuel mixture when the accelerator pedal is depressed.
Drawing air into intake system

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.
OK
Check the following items.

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

Check if air was drawn into the intake system.
Broken intake manifold gasket
Broken or disconnected vacuum hose
Improper operation of the PCV valve
Broken air intake hose
No
MUT-II Actuator test
10 EGR control solenoid valve (Refer to P.13A-62.)NGCheck the EGR control solenoid valve system. (Refer to P.13A-46,
INSPECTION PROCEDURE 33.)
INSPECTION PROCEDURE 14
The engine stalls when decelerating.
Probable cause
In cases such as the above, the cause is probably that the intake air volume is insufficient
due to a defective idle speed control (ISC) servo system.
Malfunction of the ISC system
No
MUT-II Data list
26 Idle position switch (Refer to P.13A-69.)NGCheck the idle position switch system.
(Refer to P.13A-49, INSPECTION PROCEDURE 26.)
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
45 ISC servo position

Is the idle speed control (ISC) servo position drops to 0 ± 2
steps when decelerating (engine r/min less than 1,000)?Ye sCheck the vehicle speed sensor system. (Refer to P.13A-17, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 24.)
OK
Check the following items.

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

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

Check and adjust the fixed SAS. (Refer to P.13A-79.)
No
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.)
No
MUT-II Actuator test
10 EGR control solenoid valve (Refer to P.13A-62.)NGCheck the EGR control solenoid valve system. (Refer to P.13A-46,
INSPECTION PROCEDURE 33.)
No
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.
Were the battery terminals disconnected?Ye sAfter warming-up, let the engine run at idling for 10 minutes.

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.