compression ratio MITSUBISHI SPYDER 1990 Service User Guide

ENGINE General Information
GENERAL INFORMATION
Specifications
Number of cylinders
Bore
In-line OHV, SOHC
4
Stroke1
Piston displacement
Compression ratio9.5
Firing order
Counterbalance shaft Valve timing Intake valve Opens
Closes
Exhaust valve Opens
Closes Equipped
18” BTDC
58” ABDC
58” BBDC
18” ATDC
Lubrication system Pressure feed-full flow filtration
LUBRICATION SYSTEM
Rocker arm
Oil filter
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Oilpressure, Camshaft
screen

ENGINE Troubleshooting.
TROUBLESHOOTING
SymptomProbable causeRemedy
Compression too low Cylinder head gasket blown Replace gasket
Piston ring worn or damaged Replace rings
Piston or cylinder worn Repair or replace piston and/or cylinder
block
Valve seat worn or damaged Repair or replace valve and/or seat ring
Oil pressure drop Engine oil level too low Check engine oil level
Oil pressure switch faulty ‘Replace
pressure switch
Oil filter cloggedInstall new filter
Oil pump gears or cover worn Replace gears and/or cover
Thin or diluted engine oil Change engine oil to correct viscosity
Oil relief valve stuck (open) Repair relief valve
Excessive bearing clearanceR e p l a c e b e a r i n g s
Oil pressure too high Oil relief valve stuck (closed
) Repair relief valve
Noisy valves Incorrect lash adjuster Bleed air or replace lash adjuster
Thin or diluted engine oil (low oil pressure) Change engine oil
Valve stem or valve guide worn or damaged Replace valve and/or guide
Connecting rod noise/ Insufficient oil supply Check engine oil level
main bearing noise Low oil pressure Refer to “Oil pressure drop”
Thin or diluted engine oil Change engine oil
,
Excessive bearing clearanceReplace bearings
Timing belt noiseIncorrect belt tensionAdjust belt tension replace tim-
ing belt
engine Loose engine roll stopper (Front, Rear) Retighten
ing and vibration Loose transaxle mount bracket Retighten
Loose engine mount bracket Retighten
Loose center member Retighten
Broken transaxle mount insulator
Replace
Broken engine mount insulatorReplace
Broken roll stopper insulatorReplace
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ENGINEOn-vehicle
5. Cover the spark plug hole with a shop towel etc., and
after the engine has been cranked, check that no foreign
material is adhering to the shop towel.
Caution
1.Keep away from the spark plug hole when crank-
ing.
2. If compression is measured with water, fuel,
etc., that has come from cracks inside the
these materials will become heated and gush
out from the spark plug hole, which is dangerous.
6.Set compression gauge to one of the spark plug hole s.
7. Crank the engine with the throttle valve fully open and
measure the compression pressure.
Standard (at engine speed of
1,350 (192 psi)
Limit (at engine speed of
Min. 1,020 (145 psi)
8.Measure the compression pressure for all the cylind ers,
and check that the pressure differences of the cyli nders
are below the limit.
Limit: Max. 100 (14 psi)
9. there is a cylinder with compression or a compression
difference that is outside the limit, pour a small amount
of engine oil through the spark plug hole, and repe at
the operations in steps 7 and 8.
(1) If the compression increases after oil is added , the
cause of the malfunction is a worn or damaged pisto n
ring and/or cylinder inner surface.
(2) If the compression does not rise after oil is added,
the cause is a burnt or defective valve seat, or pr essure
is leaking from the gasket.
10. Connect the crankshaft position sensor connecto r.
11. Install the spark plugs and spark plug cables.
12. Use the scan tool to erase the diagnostic troub le codes,
or disconnect the negative battery cable than
10 seconds and reconnect it.
NOTE
This will erase the diagnostic trouble code resulting from
the crankshaft position sensor connector
MANIFOLD VACUUM CHECK
1.Before inspection, set vehicles in the following co ndition:
lEn
lLig electric cooling fan, and accessories: OFF
ine coolant temperature:
lTransaxle: Neutral (P range on vehicles with
2. Set up the tachometer or connect the scan tool t o the
data link connector.
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ENGINE On-vehicle
NOTE
lIf the vehicle is parked on a slope for long, oil
in the lash adjusters will
and ‘air may
enter the high-pressure’ chamber when the vehicle
i s s t a r t e d .
lAfter the vehicle is parked for long, air may enter the high-pressure
because, the oil in the
oil passage will be gone it take a time before
the oil is supplied to the
3.If an abnormal noise does not stop by racing, check the
lash adjusters according to the following procedure s.
Stop the enaine.
of the engine to the compression
top dead center.
(3) Push the rocker arm indicated by the white arrow
mark as shown in the illustration at left and check
whether or not the arm lock goes down.
(4) Turn slowly the crankshaft
clockwise.
(5) Check the rocker arm indicated by the black arr ow
mark as shown in the illustration at left same as above
(3).(6) If the rocker arm can be lowered easily when th e
part of the rocker arm which is directly above the
top of the lash adjuster is pressed, the lash adjus ter
is defective and should be replaced with a new part .
Furthermore, when replacing the lash adjuster, blee d
all of the air from the lash adjuster and then install.
After this, check that there is no problem by check ing
in steps to (5).
NOTE
lA leak-down test can be carried out to accurately
determine whether the lash adjuster is defective
or not.
lFor the procedures for the leak-down test and
air bleeding of the lash adjuster, refer to 11
Furthermore, if the arm feels extremely stiff
and cannot be lowered when it is
the lash
adjuster is normal, so some other cause
of the abnormality.
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ENGINE (NON-TURBO)>
Scan tool 106
Code General scan tool
No.Multiple Cylinder Mlsfire
43
[Comment]Background
l Excessive engine misfire results in increased catal yst temperature.
l Severe misfire could cause catalyst damage.
l To prevent catalytic converter damage, the PCM moni tors engine misfire.
l The PCM monitors for misfire during most engine ope rating conditions.
lWhen a misfire is detected, the PCM stores a diagnostic trouble code and causes the to either flash or illuminate continuously during active misfire.
Range of Check
l MAP voltage is less than 1.60
l Engine speed is between 2200 and 2800 l Engine coolant temperature is greater than l Vehicle speed less than Set Condition
l 1000 Rev Misfire
The PCM detects misfire in more than 1.6% of the en gine cycles in a 1000 revolution
period.l 200 Rev MisfireThe PCM detects misfire in more than 15% of the eng ine cycles in a 200 revolution period.
.
Spark plugs or wires failed
l Ignition coil failed
l Crankshaft position piston rings v a l v e s
l Head gasket failed
l C r a c k e d
l Fuel lines and filter failed
l Fuel failed
l failed
l Wiring and connectors failed
l Engine coolant
l Timing belt tooth broken,
l EGR
SCAN TOOL SENSOR READ TESTS (Data list)
05 Engine coolant temperature sensor (Refer to Check the engine coolant temperature circuit.
(Refer to INSPECTION PROCEDURE 38.)
OK
SCAN TOOL SENSOR READ TESTS (Data list)
27 Intake air temperature sensor (Refer to
OK
Check the intake air temperaturecircuit.(Refer to INSPECTION PROCEDURE
SCAN TOOL SENSOR READ TESTS (Data list)
11 MAP sensor reading (Refer to
OK
OK
Check the MAP sensor circuit.(Refer to INSPECTION PROCEDURE 40.)
SCAN TOOL SENSOR READ TESTS (Data list)
Check the following connectors: 66 Oxygen sensor volts (front) (Refer to OK: Repeat and alternately whenidling.
Check the fuel pressure. (Refer to Check the harness wire between the PCM and the cran kshaft
position sensor connector.
l Check the injectors for operation sound.
l Check the injectors for fuel leakage.
l Check the evaporative emission control system.
Check the following items.
l Check the ignition coil, spark plug cables.
l Check the compression pressure.
Check the EGR
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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 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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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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E N G I N E
INSPECTION PROCEDURE 22
Too high CO and HC concentration when idling
[Comment]Abnormal air-fuel ratio is suspected.
cause
of the air-fuel ratio control system.l Deteriorated catalyst .
SCAN TOOL DTC
Are diagnostic trouble codes output Refer to INSPECTION CHART FOR DIAGNOSTICTROUBLE CODES.
NG
27 Intake air temperature sensor. (Refer to Check the intake air temperature sensor circuit.
( R e f e r t o 3 9 . ) .
N G Check the MAP sensor circuit11MAP sensor reading. (Refer to (Refer to INSPECTION PROCEDURE 40.)IOK
SCAN TOOL SENSOR READ TESTS (Data list)
83 sensor volts (rear) (Refer to l Transaxle gear range l Driving with the throttle wide open
O K :
OK
SCAN TOOL SENSOR READ TESTS (Data list)
02 sensor volts (front) (Refer to OK: 1 when suddenlv
N G Check the heated oxygensensor (rear) circuit.
(Refer to INSPECTION PROCEDURE 41.)
NG
02 sensor volts (front) (Refer to
Check the fuel pressure. (Refer to
OK
Check the following items.
l Check the injectors for operation sound.
l Check the injectors for fuel leakage.
l Check the ignition coil, spark plugs, spark plug ca bles.
l Check the compression pressure.
l Check the positive crankcase ventilation system.
l Check the evaporative emission control system.
l Check the EGR system.
NG
Check trouble symptom.
N G
Replace the three-way catalytic converter.
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