1990 MITSUBISHI SPYDER air filter

ENGINE (NON-TURBO)> Troubleshooting
Scan tool 119
Code General scan tool
No. 71Fuel System LeanProbable
51
[Comment]l Engine coolant temperature sensor Backgroundl The PCM monitors the fuel system for compliance wit h emission standards.l
Intake air temperature sensor failed- l Head gasket Range of Check
l Exhaust manifold cracked
l Engine coolant temperature is greater than l Injectors failed
l Closed loop operation
l MAP sensor failed
Set Condition
l Heated oxygen sensor failedlThe test fails if the fuel control system increases pulse width by 25% long term memory
and 12% short term compensation due to a lean condi tion.l
Fuel pressure regulator l l Fuel filter or fuel line blocked
l Fuel pump failed (insufficient discharge)
l Incorrect fuel used
__
l PCM failed
NGSCAN TOOL SENSOR READ TESTS (Data list)
05 Engine coolant temperature sensor (Refer to
SCAN TOOL SENSOR READ 27 Intake air temperature sensor to
SCAN TOOL SENSORREAD11 MAP sensor reading (Refer to
I
NG
Check the engine coolant temperature circuit.
(Refer to INSPECTION PROCEDURE 38.)
Check the intake air temperature circuit.(Refer to PROCEDURE 39.)
Check the MAP sensor circuit.
( R e f e r
63 Oxygen sensor volts (rear) (Refer to l Transaxle: gear range
SCAN TOOL SENSOR READ TESTS (Data list)
02 Oxygen sensor volts (front) (Refer to
OK: during sudden racing
NG Check the heated oxygen sensor (front) circuit.(Refer to INSPECTION PROCEDURE 42.)
SCAN TOOL SENSOR READ TESTS (Data list)
02 Oxygen sensor volts (front) (Refer to
OK: Repeat and alternately whenidling.
Check the fuel pressure. (Refer to
OK
Check the following items.
l Check the injectors for operation sound.
,
l Clean the injectors.
l Check the positive crankcase ventilation system.
l Check the fuel pump.
lCheck the fuel filter and fuel line for blockages.
l Check for exhaust gas leaks.
l Check for contamination (water, kerosene, etc.) in the fuel.
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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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E N G I N E ( N O N - T U R B O ) >
INSPECTION PROCEDURE 18
Poor accelerationProbable cause
[Comment]l Malfunction of the ignition systemDefective ignition system, abnormal air-fuel ratio, poor compression pressure, etc. are suspected.lMalfunction of air-fuel ratiol of the fuel supply P o o r a c c e l e r a t i o n
l Clogged exhaust system
SCAN TOOL DTC YES
Are diagnostic trouble codes output
NO
Refer to I N S P E C T I O N C H A R T TROUBLE CODES.
NG Check the injector Carry out procedures 19, 20, in “INSPECTION PROCEDURE
FOR DIAGNOSTIC TROUBLE CODES”. ,
Scan tool: inspection when hesitation, sag, stumble or poor
OK
Check the following items.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the compression pressure. . .
l Check the fuel filter or fuel line for clogging.
l Clogged air cleaner
l Clogged exhaust system
INSPECTION PROCEDURE 19
Surge
[Comment]Defective ignition system, abnormal air-fuel are suspected.
Probable cause
l Malfunction of the ignition system
l Malfunction of air-fuel ratio control system
l Malfunction of the EGR solenoid system
SCAN TOOL DTC
YESRefer to INSPECTION CHART FOR DIAGNOSTIC
Are diagnostic trouble codes outputTROUBLE CODES.
NO
Check the injectors for opNG Check the injector control circuit. Carry out proc edures 21,
(Refer to in “INSPECTION PROCEDURE
OK FOR DIAGNOSTIC TROUBLE CODES”.
Scan Tool: Inspection when surge occurs.
(Refer to INSPECTION PROCEDURE 35.)
OK
Check the fuel pressure. (Refer to I
OK
Check the following items.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the EGR system.
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ENGINE
6. If is not correct, troubleshoot and repair
to the table
SymptomP r o b a b l e c a u s eRemedy
l Fuel pressure too lowClogged fuel filter Replace fuel filterl No fuel pressure in fuel returnhose
Fuel leaking return side due to poorReplace fuel pressure regulator
fuel regulator valve seating or settled
spring
Low fuel pump delivery pressure
Replace fuel pump
Fuel pressure too highBinding valve in fuel pressure
regulator
fuel .
Clogged fuel return hose or pipeClean or replace or ‘pipe
7. the scan tool, with ‘the position,
the “Fuel System ,
8. Turn the ignition switch off and
‘gauge reading. Normal does
within 2 minutes! it does, observe the rate
and troubleshoot and repair-according table
SymptomProbable cause Remedy
Fuel pressure drops gradually afterLeaky injector Replace injector
engine is stopped Leaky fuel regulator valve seat Replace fuel pressur e regulator
Fuel pressure drops sharply
Checkvalve in fuel pump is held open Replace fuel pu mp
ately after engine is stopped
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9.Remove fuel pressure gauge and reinstall protective cover
onto fuel rail service valve.

ENGINE (TURBO)
AND ENGINE> Troubleshooting
Code No. Excessive to Enter Closed Loop Fuel
Control
[Comment]l Heated oxygen failedBackgroundl Injector failed
l The system reduces exhaust emissions by means of close d-loop fuel control.
l Fuel pressure regulator failedlThe engine control module checks the time taken unt il closed-loop fuel control commences.l Fuel pump failed
Check Areal Fuel filter blocked,
l Engine coolant temperature is higher than l into intake system-
l Intake air temperature is
or higher E x h a u s t - g a s l e a k
l Barometric pressure is 76 (11 psi.) or higher. l
Engine control module l Engine speed is at between about 1800 and 3500 l Volumetric efficiency is 16 62%.
l Running within air/fuel mixture ratio feedback zone .
l Monitoring time: 128
Judgement Criterial fuel injection system doesn’t enter the closed loo p control within about 30 sec.
l Monitored only once per trip.
,
Check the heated oxygen sensor (front). (Refer to Replace
Engine>
NG Repair
OKNGCheck the harness wire between the ECM and the heat ed oxygensensor connector. Repair
OK
Check meInjector. (Refer to P.lNG Replace
OKNG Repair
OKNG Repair
OK
Check the fuel pressure. (Refer to
l Check for air being drawn into me air intake system .lCheck for exhaust gas leaks (oxygen sensor fitting, exhaust
l Check the fuel pump (insufficient discharge).
Replacethe ECM.
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ENGINE (TURBO)
AND ENGINE> Troubleshooting
Code No. Fuel Trim Malfunction (Bank 1)
[Comment]
Background
lIf a malfunction occurs in the fuel system, the fue l compensation value becomes too largeor too small.lThe engine control module checks whether the fuel c ompensation value is within a specified
range.
Check Areal Under the closed loop air-fuel ratio control
l Intake air temperature is or higher
l Barometric pressure is 76 (11 psi.) or higher.
Judgement CriterialLong-range fuel correction has continued to be not lower than or not higher than
-12.5% for 10 sec.
lShort-range fuel correction has continued to be not lower than or not higher than-10.0% for 10 sec.
SCAN TOOL Data list 13 Intake air temperature sensor (Refer to
Probable
l V o l u m e ‘ a i r l Injector failed .Incorrect fuel pressure
Air drawn gaps seals,’ etc.
Heated oxygen sensor
Engine coolant temperature sensor failed, Intake air, temperature sensor f a i l e d Exhaust gas leaks
E n g i n e
NG Check the intake air temperature circuit malfuncti on. (Refer to INSPECTION PROCEDURE TROUBLE CODE
NGSCAN TOOL Data list Check the engine coolant malfunction (Refer
21 Engine coolant temperature sensor (Refer to to INSPECTION PROCEDURE
OKTROUBLE CODE
SCAN TOOL Data list
25 Barometric pressure sensor (Refer to
OK
NG Check the barometric pressure circuit INSPECTION PROCEDURE D I A G N O S T I C
TROUBLE CODE
NGCheck the injector (Refer to Replace
OK N G
Check the following connectors: Repair
NG Repair
OK
Check the fuel pressure (Refer to
OK
SCAN TOOL Data list
Morethan zero Check if air was drawn N G Repair81 Long-term fuel compensation (Refer to l fuel trim more or less than zero?I
sensor(Refer to l Does the tester indi-
cate more than the
standard value?
Yes
Replace the volume airflow sensor.
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lCheck for fuel leakingfrom injectors.lCheck for contamina-
tion (water, kerosene,
etc.) in the fuel.
OK
Replace the ECM
into the intake
OK
SCAN No
12 Volume air flow sensor(Refer to l Does the tester indi-
cate less than the
standard value?
l Check for blockedinjectors.l Check for fuel filter
and fuel line block-
ages.l Check the fuel pump(insufficientdis-charge).l Check for exhaust
gas leaks (oxygen
sensorfitting, exhaust
manifold cracks, front
pipe cracks, etc.)lCheck for contamina-
tion (water, kerosene,
etc.) in the
OK
Replace

ENGINE (TURBO)
AND ENGINE> T r o u b l e s h o o t i n g
INSPECTION PROCEDURE 15
Hesitation, sag or stumbleProbable
[Comment]Malfunction of the ignition system
In cases such as the above, the cause is probably t hat ignition system, air/fuel or l of pressure is defective. of the fuel l Malfunction of the system Poor compression Malfunction of the turbocharger,
Arediagnostic trouble codesoutput
Check the injectors for operationsound.(Refer to
OK
Refer to INSPECTION FOR DIAGNOSTICTROUBLE CODES.. .
Check the injector circuit malfunction PROCEDURE FOR DIAGNOSTIC
Check the ignition timing. Engine (Turbo)>
(Refer to GROUP On-vehicle Service.)
Check the ignition timing.
(Refer to GROUP 11 On-vehicle Service.)
Check that the crankshaft position and cover installed properly.
OK
Scan Tool: Inspection when hesitation, sag, stumble or pooracceleration occurs. (Refer to INSPECTION
PROCEDURE 42.)
IOK
Check the fuel pressure. (Refer to
O K
Check the following items.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Check supercharging pressure.
l Check intake charge pressure control system.
l Check rotating resistance of turbocharger turbine w heel. (Does the wheel rotate smoothly?)
Check the EGR system.l Check the compression pressure.lCheck the fuel filter or fuel line for clogging.
INSPECTION PROCEDURE 16
Acceleration shock
[Comment]
In cases such as the above, the cause is probably t hat there is an ignition leak accompanying
the increase in the spark plug demand voltage durin g acceleration.
Probable cause
M a l f u n c t i o n system
SCAN TOOL DTC
Are diagnostic trouble codes output
NORefer to
INSPECTION CHART FOR DIAGNOSTIC
T R O U B L E C O D E S .
,
Check the following items.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Check for occurrence of ignition leak.
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ENGINE (TURBO)
AND
ENGINE> Troubleshooting
INSPECTION PROCEDURE 17
Probable causeI
[Comment]l Malfunction of the system
Malfunction of the system is suspected.
Are diagnostic trouble codes output
YESRefer to INSPECTION FOR DIAGNOSTICTROUBLE CODES.
Check theidle air control motor for operation sound Engine (Refer to Check the idle air control motor for operation soun d Engine>. (Refer to
SCAN TOOL Data list
14 Throttle position sensor (Refer to
OK
Check the idle control system malfunction (Refer t o INSPECTION PROCEDURE FOR DIAGNOSTIC TROUBLE CODE
Check the throttle position circuit malfunction (Refer to PROCEDURE FOR DIAGNOSTIC TROUBLE 20.)
NG,
SCAN TOOL Data list Check closed position switch system.
26 Closed throttle position switch (Refer to (Refer to INSPECTION PROCEDURE FOR DIAGNOSTICTROUBLE CODE .
. .
Clean the throttle valve area. (Refer to
INSPECTION PROCEDURE 18
Poor acceleration Probable cause I
[Comment]
Defective ignition system, abnormal air-fuel ratio, poor compression pressure, etc. are l Malfunction of the Ignition system Malfunction of air-fuel ratio control l Malfunction of the fuel supply system Poor acceleration
l C l o g g e d e x h a u s t s y s t e m
l Malfunction ‘of turbocharger system .
SCAN TOOL DTC
Are diagnostic trouble codes output
YESRefer to INSPECTION CHART FOR DIAGNOSTICTROUBLE CODES.
Check the injectors for opNG
(Refer to PROCEDURE FOR DIAGNOSTIC TROUBLE
OK
Check the ignition timing. Engine (Turbo)>
(Refer to GROUP A On-vehicle Service.)
Check the ignition timing. Engine>
Check that the crankshaft position sensor and timi ng belt cover are
installed
(Refer to GROUP On-vehicle Service.)
OK
Scan tool: Inspection when hesitation. stumble or poor acceleration occur. (Refer to INSPECTIONPROCEDURE 42.)I
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 supercharging pressure.
l Check intake charge pressure control system.
l Check rotating resistance of turbocharger turbine w heel. (Does the wheel rotate smoothly?)
l Check the compression pressure.
lCheck the fuel filter or fuel for clogging.
l Broken air intake hose
Clogged air cleaner
l Clogged exhaust system
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