1991 MITSUBISHI 3000GT Service Manual

ENGINE - Specifications
/
L
L/
Items
Connecting rod bearing
Oil clearancemm (in.)
Crankshaft main bearing
Oil clearancemm (in.)
Crankshaft
Pin O.D.
mm (in.)
Journal O.D.mm (in.)
Out-of-roundness of journal and pin
mm (in.)
Taper of journal and pin
mm (in.)
End playmm (in.)
Oil pressure at curb idle speed
kPa (psi)
[Conditions: oil temperature is 75 to 90°C
(167 to
194”F)l
Standard value
0.016- 0.046 (.0006- .0018)
0.019 - 0.044 (.0007 - .0017)
49.9 (I ,965)
59.9 (2.358)
Less than 0.003 (.00012)
Less than 0.005 (0002)
0.05 - 0.25 (0020 - .0098)
80 (I 1.4) or more
Limit
0.1
(.004)
0.1 (.004)
0.3 (.012)
Oil pump
Side clearancemm (in.)
Body clearance0.100-0.181 (.0039-.0071)
Side clearance0.040 - 0.095 (.0016 - .0037)
Relief spring
Free lengthmm (in.)43.8 (1.724)
Load
137 N (8.3 Ibs.)]mm (in.)40.1 (1.579)
Drive belt
For alternator (Vehicle without air
conditioner)
Deflectionmm (in.)
Inspection
4.0-5.5(.157-,216)
New belt3.5-4.0(.138-,157)
Used belt4.0-5.0 (.157- ,197)
TensionN (Ibs.)
Inspection350 - 600 (77 - 132)
New belt650
- 850 (143 - 187)
Used belt450
- 600 (99 - 132)
For alternator and air conditioner
compressor
Deflectionmm (in.)
Inspection
4.0-5.5(.157-,216)
New belt3.5-4.0 (1388.157)
Used belt4.0-5.0(.157-,197)
For power steering pump
Deflection
mm (in.)9.0
- 11 .o (354 - ,433)
Timing belt
Amount of projection of auto tensioner3.8-4.5(.149-,177)rodmm (in.)(distance between the tensioner arm andauto tensioner body)
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11-8ENGINE - Specifications / Special Tools
SEALANTS
MIKE- -
Items
Oil pan
Oil seal case
Oil pressure switch
Specified sealant
MITSUBISHI GENUINE Part No. MD9971
10 or equivalent
Oil pressure gauge unit
Rocker cover3M ATD Part No.8660 or equivalent
SPECIAL TOOLSMIlDA--
MD998051-01
Loosening and tightening of cylinder head bol
seal installer
compressor
Camshaft oilsealInstallation of camshaft oil seal
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ENGINE - Special ToolsII-9
Use withMD998765
Removal and installation of piston pinUse with MD998764
Supporting thecrancrankshaft bolt and
pulley areremoved
orreinstalled. Use together with MB990767-01
Tensioner pulley
socket wrenchAdjustment of timing belt
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II-IOENGINE - Troubleshooting
TROUBLESHOOTINGmiwm
SymptomProbable cause
RemedyI,aJ
Compression too low) Cylinder head gasket blown1 Replace gasketI
Piston ring worn or damage
Piston or cylinder worn
Replace rings
Repair or replace piston and/or cylinder
block
Valve seat worn or damage
Repair or replace valve and/or seat ring
3il pressure drop
Engine oil level too lowCheck engine oil level
Oil pressure switch faulty
Oil filter clogged
Replace oil pressure switch
Install new filter
Oil pump gears or cover worn
Thin or diluted engine oilReplace gears and/or cover
Change engine oil to correct viscosity
1 Oil relief valve stuck (opened)) Repair relief valve
Excessive bearing clearance
Replace bearingsIbOil relief valve stuck (closed)
Incorrect lash adjusterRepair relief valve
Replace lash adjuster Oil pressure too high
Noisy valves
Thin or diluted engine oil (low oil pressure)Change engine oil
Valve stem or valve guide worn or damageReplace valve and/or guide
Connecting rod noise/
nain bearing noiseInsufficient oil supplyCheck engine oil level
Thin or diluted engine oilChange engine oil
Excessive bearing clearanceReplace bearings
Timing belt noise
Incorrect belt tensionAdjust belt tension
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ENGINE - Service Adjustment ProceduresII-IISERVICE ADJUSTMENT PROCEDURES

AlternatorTension pulley
IIdler pulley/
Tension pulleyCrankshaftpulleyOlFOOO

Tenston pulley
Air conditionerCrankshaftcompressor pulleypulleyOlFOO8
,
MllFMBGDRIVE BELTS TENSION ADJUSTMENT
(1) Check that the belts are not damaged and are properly fit
,into the pulley grooves.
Caution1. When installing the V-ribbed belt, check that the
V-ribs are properly fit without misalignment.
2. If creaking or slippage is observed, check the belt
for wear, damage, or breakage on the pulley contact
surface, check the pulley for scoring, in addition to
sag inspection.3. Check that the V-ribbed belt is not resting on the
tension pulley or idler pulley flange.
(2) Apply 100 N (22
Ibs.) force to the belt back midway
between the pulleys as shown in the illustration, measure
the deflection or by using a belt-tension gauge, check the
belt’s tension.
Standard value:
Tension350-600650-850450-600N (Ibs.)(77-132)(143-187)(99-132)
For P/S
pump
ItemsAdjustment valueCheck valueNew beltUsed belt
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II-12ENGINE - Service Adjustment Procedures-
r
AdJl
bolt
Alternator wllev
haft
Fixing nutOlFOOO8
Alternator pulley
Adjusting bolt
/Crankshaftpulley
Air contionercompressorpulleyw Tension pulleyFlxtng nutOlN007.
Crankshaft pulleyOlN007TENSION ADJUSTMENT OF THE ALTERNATOR DRIVE
BELT
I(1) Remove front under cover panel ’
aero> (Refer to GROUP 51 - Aero Parts.).\\
3 ’
(2) Remove under covers (front L.H., side L.H.).
(3) Loosen tension pulley fixing nut.
(4) Adjust belt deflection with adjusting bolt.
(5) Tighten fixing bolt.
(6) Run the engine one time or more.
(7) Check the belt tension. Readjust, if necessary.
(8) Install under covers.
DEFLECTION ADJUSTMENT OF THE ALTERNATOR AND
AIR CONDITIONER COMPRESSOR DRIVE BELT with air conditioner>
(1) Use straight handle box wrench to loosen tension pulley
fixing nut.
(2) Adjust belt deflection with adjusting bolt.
(3) Use straight handle box wrench to tighten fixing nut.
(4) Run the engine one time or more.
(5) Check the belt deflection. Readjust, if necessary.
DEFLECTION ADJUSTMENT OF POWER STEERING PUMP
DRIVE BELT(1) Insert an extension bar (insertion depth 12.7 mm), etc. into
the opening at the end of the tension pulley bracket.
(2) Loosen the tension pulley fixing bolts in the order of B and
(3)
iove the extension bar installed to the tension pulley in the‘LJdirection of arrow to adjust the belt tension.
(4) Tighten the tension pulley fixing bolts in the order of A and
8.Tightening torque: 35
- 50 Nm (25 - 36 ftlbs,)(5) Give the crankshaft two turns in normal direction (clock-
wise) to run in the belt.
(6) Check the belt deflection. Readjust, if necessary.
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ENGINE - Service Adiustment ProceduresII-13
I_ ianltion tlminaI!H Connector for Igdpstment 6rown)
4tll II -7FUO9371IGNITION TIMING ADJUSTMENTMllFLAF
(1) The vehicle should be prepared as follows before the
inspection and adjustment.
lEngine coolant temperature: 80 - 95°C (176 - 205°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: neutral
(P for A/T)l Steering wheel: neutral position
(2) Insert a paper clip to the connector, and connect a
tachometer to the paper clip.
NOTEDo not use the Multi-use tester.
If tested with the Multi-use tester connected to the
diagnosis connector, the ignition timing will not be the basic
timing but be ordinary timing.
(3) Set the timing light.
(4) Start the engine and run at idle.
(5) Check curb idle speed.
Curb idle speed: 700
f 100 rpm
NOTEThe engine speed indicated is a third of actual speed. In
other words, the reading of the tachometer times 3 is actual
speed.
(6) Turn OFF the ignition switch.
(7) Using a jumper wire, ground the ignition timing adjusting
terminal.
NOTEGrounding this terminal sets the engine to the basic ignition
timing.
\(8) Start the engine and run at idle.
(9) Check basic ignition timing.
Basic ignition timing: 5” BTDC
k 2”
(10)lf not within the standard value range, loosen the crank
angle sensor mounting nut and adjust by turning the crank
angle sensor. Turning it to the counterclockwise retards
timing, and to the clockwise advances it.
(1 l)After adjustment, tighten mounting nut taking care not to
move the crank angle sensor.
(12)Turn OFF the ignition switch.
(13)Disconnect the jumper wire connected at step (7).
(14)Start and run the engine at curb idle speed.
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11-14ENGINE - Service Adjustment Procedures
(15)Check to be sure that the idling ignition timing is the correct
timing.
Actual ignition timing: Approx. 15” BTDC
NOTE:d
(1) Ignition timing is variable even under normal operation.
(2) And it is automatically advanced at higher altitudes.
CURB IDLE SPEED INSPECTIONMllFMAB
(1) The vehicle should be prepared as follows before the
inspection.
lEngine coolant temperature: 80 - 95°C (176 - 205°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: neutral
(P for A/T)l Steering wheel: neutral position
(2) Connect a tachometer. (Refer to P.l l-1 3.)
(3) Set a timing light.
(4) Using a jumper wire, ground the ignition timing adjusting
terminal.
(5) Start the engine and let it idle.
(6) Check whether or not the ignition timing is the standard
value; if not, adjust.
Standard value: 5” BTDC + 2”
NOTECheck the ignition timing with the Multi-use tester not
connected to the diagnosis connector.
(7) Remove the jumper wire from the ignition timing adjusting
terminal.
(8) When using the Multi-use tester, turn OFF the ignition
switch and connect the tester to the diagnosis connector.
(9) Idle the engine for two minutes.
(10)Check the idle speed.
Curb idle speed:
700 + 100 rpm
NOTE(1) The idling speed is automatically regulated by the
idle-speed control system.
(2)’ The engine speed indicated is a third of actual speed. In
other words, the reading of the tachometer times 3 is
actual speed.
(1l)lf not within the standard value range, refer to GROUP 13 -Service Adjustment Procedures.
d
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