1990 MITSUBISHI SPYDER check engine

ENGINE (NON-TURBO)> Troubleshooting
INSPECTION PROCEDURE 8
Unstable idle (Rough idle, hunting)Probable cause
[Comment] Malfunction of the ignition system
In cases such as the above, the cause is probably t hat the ignition system,l Malfunction of air-fuel ratio system
idle air control motor or compression pressure is d efective.
l Malfunction of the system
Because the range of possible causes is broad, insp ection is narrowed down to simple items.
l Malfunction of the evaporative emission
purge solenoid system
l Malfunction of the EGR system
l Poor compression
l Drawing air into exhaust system
W ere the battery terminals disconnected recently?
SCAN TOOL DTC
Are diagnostic trouble codes output
NO Refer to
INSPECTION CHART FOR DIAGNOSTICTROUBLE CODES.
YES
Inspection when hunting occurs.
(Refer to INSPECTION PROCEDURE 31.)
SCANTOOL Actuator test
07 motor (Refer to
OK
NG Check the idle air control motor (Refer to P. INSPECTION PROCEDURE FOR DIAGNOSTIC TROUBLE CODE
SCAN TOOL Specialfunction
“Reset
I
Check trouble symptoms.
OK
Scan tool: Inspection when idle speed is unstable. (Refer
to INSPECTION PROCEDURE 32.)
OK
Check the injector control circuit: (Carry out pro cedures 19, 20, 21, in “INSPECTION PROCEDURE
FOR DIAGNOSTIC TROUBLE CODES”.)
Check the following items. l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the purge control system.
l Check the EGR svstem.
l Check the compression pressure.
l Check if foreign materials (water, alcohol, etc.) g ot into fuel.
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E N G I N E
INSPECTION PROCEDURE 9
Idle speed is high. (Improper idle speed)
[Comment] lIn such cases as the above, the cause is probably that the intake air volume during idle is’ ltoo great. Intake manifold vacuum leak b o d y
SCAN TOOL DTC
Are diagnostic trouble codes output
NO
07 motor (Refer to
NG
Refer to INSPECTION CHART FOR DIAGNOSTICTROUBLE CODES.
Checktheidleaircontrolmotorcircuit.PROCEDURE FOR DIAGNOSTIC TROUBLE
OK
SCAN TOOLSpecial function
“Reset
Check trouble symptoms.
NG
SCAN TOOL SENSOR NGCheck the engine coolant temperature circuit.(Refer to INSPECTION
OK
SCAN TOOL OUTPUT clutch relay (Refer to
OK
NGCheck the switch and compressor clutch relay to INSPECTION PROCEDURE 26.)
Check the throttle body minimum air flow.
(Refer to
INSPECTION PROCEDURE 10
Idle speed is low. (Improper idle speed) Probable ca use
,
[Comment]l control motor In cases such as the above, the cause is probably that the intake air volume during idling is l
Malfunction of the’ throttle body
too small.
SCAN TOOL DTC
YESRefer to INSPECTION CHART FOR DIAGNOSTIC
Are diagnostic troublecodesoutputTROUBLE CODES.
SCAN TOOL Actuator test
07 motor. (Refer to
OK
NG
PROCEDURE FOR DIAGNOSTIC TROUBLE CODE
SCAN TOOL Special function
“Reset
Check trouble
OK
Check the engine coolant temperature circuit. (Refer to INSPECTION PROCEDURE 36.)
SCAN TOOL INPUT STATE TESTS
list) position switch (transaxle range switch)
(Refer to
OK Checktransaxle range sensorcircuit.
INSPECTION
PROCEDURE 25.)
Check the throttle body minimum air flow.
(Refer to
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ENGINE,
INSPECTION PROCEDURE 11When the engine is cold, it stalls at idle. (Die ou t)
[Comment]lMalfunction of the idle air control
In such cases as the above, the cause is probably t hat the air/fuel mixture is inappropriate when l Malfunction of the fhroffle body the engine is cold, or that the intake air volume i s insufficient..l Malfunction of the injector System l Malfunction: system
W ere the battery terminals disconnected recently?
NO
SCAN TOOL DTC
.After warming-up, let the engine run at idling for 10 minutes.I
,
Are diagnostic trouble codes output?TROUBLE CODES
N OI -.: .
Does the engine stall right after the accelerator p
edal is
Check the throffle body minimum air (Refer to released
NO . . . N O Check for unstable idle (Rough hunting)Is engine-idling stable after the warming-up?
YES(Refer to INSPECTION 8.)
SCAN TOOL Actuator test
07 motor (Refer to
OK NG
Check the idle air control motor circuit. (Refer t
o INSPECTION PROCEDURE FOR TROUBLE CODE
SCAN TOOL Special function
“Reset
Check trouble symptoms.
NG
OK
.
Check the injector control circuit. Carry procedures 19, in “INSPECTION PROCEDUREFOR DIAGNOSTIC TROUBLE
Check the fuel pressure. (Refer to
Check the following items.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the compression pressure.
l Check the engine oil viscosity.
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E N G I N E
INSPECTION PROCEDURE 12 , .
. .
When the engine is hot, it stalls at idle. (Die out )
[Comment]l Malfunction of the ignition In cases such as the above, the cause is probably t hat ignition system, mixture, idle l
air control motor or compression pressure is defect ive.Malfunction control M a l f u n c t i o n o f t h e s y s t e m In addition, if the engine stalls, the cause
mayalso be a defective connector contact.l into intake system
l Improper connector contact
W ere the battery terminals disconnected recently
NO
YES After warming-up, let the engine run at idling for 10 minutes.
SCAN TOOL DTC
Are diagnostic trouble codes output?
NO
SCAN TOOL Actuator test
07 motor. (Refer to
OK YES
N G
Refer to INSPECTION CHART FOR DIAGNOSTICTROUBLE CODES.
Checktheidleaircontrolmotorcircuit. INSPECTIONPROCEDURE FOR DIAGNOSTIC TROUBLE CODE
SCAN TOOL Special function
“Reset
Check trouble symptoms.
NG
Check the injector for operation sound.
(Refer to Check the injector control circuit. Carry out proc edures 20, in “INSPECTION PROCEDURE
FOR DIAGNOSTIC TROUBLE CODES”.
Does the engine stall right
released
NO.
Does the engine stall easily again
YES
Scan tool: Inspection when engine stalls when the e ngine
is warm and idling (Refer to INSPECTIONPROCEDURE 33.)
OK
Check the throttle body minimum air flow (Refer to
While carrying out an intermittent malfunction simulation test (Refer
to GROUP 00 How to Cope with Intermittent Malfunctions), check
for sudden changes in the signals shown below.
l Crankshaft position sensor and
l MAP sensor signal Fuel pump signall Injector drive signal l power supply voltage
Check the following items.
l
Check the ignition coil, spark plugs, spark plug ca bles.
l Clean the injectors.
l Check the compression pressure.
l Check if foreign materials (water, alcohol, etc.) g ot into fuel.
INSPECTION PROCEDURE 13
The engine stalls when accelerating. (Pass out) Probable cause
[Comment]l
Injectors failedIn cases such as the above, the cause is probably m isfiring due to a weak spark, or an inappropriatelMalfunction of the ignition system
air/fuel mixture when the accelerator is depressed.
YESRefer to INSPECTION CHART FORDIAGNOSTIC
Arediagnostic trouble codes outputTROUBLE CODES.
NO
Check the following items.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Clogged injectors

ENGINE (NON-TURBO)>
INSPECTION PROCEDURE 14. .. .
The engine stalls when decelerating.P r o b a b l e c a u s e
[Comment]In cases such as the above, the cause is probably t
hat the intake air volume is insufficient due
to a defective idle air control motor system. l Malfunction of the system
W ere the battery terminals disconnected recently?YES After warming-up, let the engine run at idling for
SCAN TOOL DTC
Are diagnostic trouble codes output?
OK
Refer to I N S P E C T I O N FOR TROUBLE CODES.. .
SCAN TOOL SENSOR07 Throttle position (Refer to
NO
NGCheck the throttle position sensor circuit.
(Refer to INSPECTION PROCEDURE 43.)
Check the following items. l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the throttle body minimum air flow.
INSPECTION PROCEDURE 15
Hesitation, sag or stumble
[Comment]In cases such as the above, the cause is probably t hat ignition system, air/fuel mixture or
compression pressure is defective.
Probable cause
Malfunction of the ignition Malfunction of air-fuel ratio control l Malfunction of the fuel supply l of the EGR. solenoid l P o o r
Are diagnostic trouble
codes output
Check the injectors for opNG
(Refer to Check the injector control circuit. out procedures 20, 21, in’ INSPECTION PROCEDUREFOR DIAGNOSTIC TROUBLE CODES”.
Scan Tool: Inspection when hesitation, sag, stumble or pooracceleration occur. (Refer to INSPECTIONPROCEDURE 34.)
OK
Check the fuel pressure. (Refer to
OK
Check the following items.l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the EGR system.
l Check the compression pressure.
l Check the fuel filter or fuel line for clogging.
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ENGINE Troubleshooting
INSPECTION PROCEDURE 20
Knocking
[Comment]l Defective knock sensorIn cases such as the above, the cause is probably t hat the detonation control is defective or l
the heat value of the spark plug is inappropriate. Inappropriate value of the
YES
Are
diagnostic troublecodesRefer to INSPECTION CHART FOR DIAGNOSTIC
outputTROUBLE CODES.
NO
SCAN TOOL SENSORNG
09 Knock sensor volts (Refer toCheck the knock sensor circuit (Refer to INSPECTION
PROCEDURE FOR DIAGNOSTIC TROUBLE
OK
Check the following items. l heat ranae
l Check ‘if (water, alcohol, etc.) got into fuel.
Dieseling cause
[Comment]Fuel leakage from injectors is suspected. l
Fuel leakage from injectors
Check the injectors for fuel leakage.
R e v i s i o n

ENGINE ( N O N - T U R B O ) >
INSPECTION PROCEDURE 25
Transaxle range sensor circuit
[Comment]The transaxle range sensor inputs the condition of the selector lever, i.e. whether it is in or range or in some other range, to the PCM.
The PCM controls the idle air control motor based o n this input.Improper connector contact, open circuit
Check the transaxle range sensor. (Refer to GROUP On-vehicle Service.) Replace.
lDisconnect the connector,and measure atthe harness
A-l
OK
Check trouble symptom.
OK
Replace the PCM.
Check harness wire betweenN G
PCM transaxle rangesensor connector.
O K
Replace the PCM.
,
INSPECTION PROCEDURE 26
A/C switch and A/C compressor clutch relay system
motor, and also operates the A/C compressor magneti c clutch.Probable cause
l Malfunction of A/C control l Malfunction of A/C switch Improper connector open short-circuited harness wire
l Malfunction of PCM
NG
OKCheck the A/C compressor clutch relay.
Measure at the PCM
l
(Refer to GROUP 55 On-vehicle Service.)
Disconnect the connector, and measure at the harnes s
Replace
Check the
system. (Refer to GROUP 55
side.lVoltage between 64 and ground, and 38 and ground(Ignition switch: ON)
(A/C switch: ON)
OK: Battery positive voltage
l Connect a jumper wire between 64 and ground.
(Ignition switch: ON)
(A/C switch: ON)
OK: A/C compressor clutch turns ON.
OK1NG RepairA-l 06,A-l 07
OK
Check trouble symptom.
Replace the PCM.
NG
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ENGINE (NON-TURBO)>
INSPECTION PROCEDURE 27
Fan motor relay system (Radiator fan, condenser fan)
[Comment]l Malfunction of fan motor relay
The fan motor relay is controlled by the power tran sistor inside the PCM turning ON and OFF l
Malfunction of fan motor
.improper connector contact, open or
short-circuited wire
l Malfunction of the PCM
Measure at PCM connectors
lDisconnect the connector, and measure at the harnes s RepairA-lA-l 07side.lVoltage between 19 and ground, 55 and ground and
69 and ground (Ignition switch: ON)
OK: Battery positive voltage
lConnect a jumper wire between 19 and ground, and
69 and ground (Ignition switch: ON)
OK:Radiator fan and condenser fan run at high speed.lConnect a jumper wire between 55 and ground (Igniti on
switch: ON).
OK
Check symptom.
1Replace the
OK: Radiator fan runs at low speed.
lCheck the radiator fan circuit (Refer to ELEC-TRICAL WIRING.) (Refer to ELECTRICAL WIRING.)
l Check the A/C condenser fan circuit.
(Refer to ELECTRICAL WIRING.) (Refer to ELECTRICAL WIRING
INSPECTION PROCEDURE 28
Ignition circuit system1
[Comment]
The PCM interrupts the ignition coil primary curren t by turning the ignition power transistor inside
the PCM ON and OFF.
TSB
Malfunction of relay Improper connector contact, circuit Or
short-circuited
l Malfunction of the PCM
NG
Measure at the ignition coil connector Check the following RepairlDisconnect the connector and measure at the harnessside. OK SCAN TOOL Actuator test
relay relay) is turned on and off every 1
[Measure with relay on.]
Check trouble
C h e c k t h e h a r n e s s b e t w e e n relay OK relay) and ignition coil switch Repair, if
Check the harness wire between PCM and ignition coi l
connector. if