1991 MITSUBISHI 3000GT Service Manual

ENGINE - Service Adjustment Procedures11-15COMPRESSION PRESSURE CHECKMllFFAK
(1) Before checking compression, ensure that engine oil, the
starter motor, and battery are all in normal operating
condition.
(2) Start the engine and wait until engine coolant temperature
has risen to 80
- 95°C (176 - 205°F).
(3) Remove the all spark plugs.
(4) Crank the engine to remove any foreign objects in the
cylinders.
CautionCover the spark plug holes with shop towel, etc., in
order to keep expelled foreign objects from flying out,and keep away from the holes. When measuring
compression with water, oil, or fuel having entered the
cylinder through a crack, etc., these will come flying out
of the spark plug hole hot and fast, so be sure to take
the proper precautions.(5) Set the compression gauge to the spark plug hole.
(6) Holding the throttle valve full open, crank the engine and
measure compression.
Limit:
min. 980 kPa (139 psi)
min. 810 kPa (115 psi)(7) Perform (5) and (6) above for all the cylinders, ensuring that
compression pressure differential for each of the cylinders
is within the specified limit.
Limit: max.
100 kPa (14 psi)
(8) If a cylinder’s compression or pressure differential exceeds
the limit, add a small amount of oil through the spark plug
hole and repeat steps (5)
- (7).@If the addition of oil brings compression up, it is possible
that there is
harmf,uI friction between the piston ring
and cylinder wall.@If not compression up, valve seizure, poor valve seating,
or a compression leak from the gasket are all possible.
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11-16ENGINE - Service Adjustment Procedures
MANIFOLD VACUUM INSPECTION
MllFNAR
(1) The vehicle should be repaired as follows before the
inspection.
lEngine coolant temperature: 80 - 95°C (176 - 205°F)‘dl 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-l 3.)
(3) Disconnect the vacuum hose from the nipple for taking off
fuel pressure regulator vacuum from the air intake plenum.
(4) Conncet a three-way joint between the removed vacuum
hose and the nipple and connect a vacuum gauge to the
joint.
(5) Start the engine and check that idle speed is within the
standard value range.
(6) Check the manifold vacuum.
Standard value:
*
Approx. 520 mmHg (20 in.Hg)
Approx. 495 mmHg (19 in.Hg)LASH ADJUSTERS CHECK
Ml 1 FEAFIf an abnormal noise is heard from the lash adjusters, check as
follows.
(1) After warming up the engine, stop it.
(2) While installed to the cylinder head, press the part where
the rocker arm contacts the lash adjuster at the very top. If
the adjuster is normal, the part pressed will feel very hard.
d
(3) If it easily moves all the way downward when pressed,
there is a malfunction of the lash adjuster and it should be
replaced with a new one.
(4) If it feels spongy or elastic, probably oil with air mixed in it
has entered the lash adjuster. Check whether the amount
of oil is too much or is not enough and the cause of air
becoming mixed into the oil is a damaged oil screen or oil
screen gasket.
(5) After repairing the cause of the air leak, warm up the engine
and then drive the vehicle at low speed for a while. Stop the
engine and leave it off for a few minutes; then restart the
engine and drive at low speed. Repeat this procedure
several times during the course of about one hour so as to
remove the air from the oil.
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ENGINE - Engine AssemblyII-17
ENGINE ASSEMBLY
/REMOVAL AND INSTALLATION
I
Pre-removal Operationl Release of Residual Pressure from HighPressure Fuel Hose(Refer to GROUP 13 -Service AdjustmentProcedures,)l Removal of Cruise Control Pump andLink Assembly(Refer to GROUP 13 - Cruise Control.)l Removal of Hood(RefertoGROUP42A-Hood.)
l
Removal of Air Hose and Air Pipe (Refer to GROUP 15 - Inter Cooler.)l Removal of Front Exhaust Pipe(Refer to GROUP 15 - Exhaust Pipe and Main Muffler.l Removal of Transaxle Assembly(Refer to GROUP 22, 23 -Transaxle Assembly.)l Removal of Radiator(Refer to GROUP 14-Radiator.)
Post-installation Operationl Installation of Radiator(Refer to GROUP 14 - Radiator.)l Installation of Cruise Control Pump andLink Assembly(Refer to GROUP 13 -Cruise Control.)l Installation of Transaxle Assembly(Refer to GROUP 22,23 -Transaxle Assembly.)l lnstallatron of Front Exhaust Pipe(Refer to GROUP 15 - Exhaust Pipe and Main Muffler.)l Installation of Air Hose and Air Pipe (Refer to GROUP 14 - Inter Cooler.)l Installation of Hood(Refer to GROUP 42A- Hood.)l Supplying of Engine Oil(Refer to GROUP 00 - Maintenance Service.)l Adjustment of the Accelerator Cable(Refer to GROUP 13 - Engine Control.)
MllSA-B
4 ft.lbs.
6
40-45 Nm
29 - 33 fklbs.
Removal steps
1. Connection of accelerator cable11. Drive belt (Alternator and air conditioner)
2. Connection of brake booster vacuum hose(Refer to P.l l-l 1.)
3. Connection of booster vacuum12. Drive belt (Power steering)
hose
(Referto P.l l-l I.)4. Connection of fuel return hose13. Connection of alternator harness
5. Connection of fuel high pressure hose14. Oxygen sensor connector
6. Connection of ground cablel *15. Air conditioner compressor
7. Solenoid valve assembly4w
16. Power steering oil pump
8. Connection of vapor hose17. Oil pressure switch connector (Power steer-9. Connection of heater hoseing)10. EGR temperature sensor connector18. Connection of oil cooler pipes

OlFOO43
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II-18ENGINE - Engine Assembly
19. ISC servo connector
20. TPS connector
21. Oil pressure switch and oil
pressure gauge unit connector22. Fuel injector harness connector
23. Knock sensor connector
24. Crankshaft angle sensor connector
25. Engine coolant temperature
switch connector (Air conditioner)
26. Engine coolant temperature
sensor connector
27. Engine coolant temperature
gauge unit connector
28. Condenser connector
29. Ignition coil connector
30. Power transistor connector
31. Fuel injector connector
32. Variable induction motor connector

33. Oxygen sensor connector 28
2930lOO-
120 Nm72 - 87 ft.lbs.
70 Nm
,51 ftlbs
** l * 34. Engine mounting bracket
35. Rear roll stopper bracket and engine
connection bolt36. Front roll stopper bracket and engineconnection bolt** l a 37. Engine assembly35 Nm
25 ft.lbs.
?I,---R
50-60 Nm36 - 43 ftlbs.
OlFOO19
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ENGINE - Enaine AssemblvII-19
Engine mount bracketSERVICE POINTS OF REMOVALMllSBEH
15. DISCONNECTION OF Ail? CONDITIONER COMPRES-SOR
/ 16. POWER STEERING OIL PUMP
Disconnect air conditioner compressor and power steering
oil pump (with the hose).
NOTEThe removed air conditioner compressor and power steer-
ing oil pump should be fastened (by using rope, etc.) in
.aposition that will not interfere with the removal/installation
of the engine assembly.
34. REMOVAL OF ENGINE MOUNT BRACKETBefore removing the engine mount bracket installation bolt,
use a chain block or similar arrangement to suspend the
engine assembly (to the extent that there is no looseness of
the chain).
37. REMOVAL OF ENGINE ASSEMBLYAfter checking that the cables, hoses, harness connectors,
etc. are all removed, slowly raise the chain block to lift the
engine assembly upward out of the engine compartment.
SERVICE POINTS OF INSTALLATIONMl
1SDBC
37. INSTALLATION OF ENGINE ASSEMBLYWhen mounting the engine, check to be sure that the
cables, hoses, harness connectors, etc. are all in the correct
position.
34. INSTALLATION OF ENGINE MOUNT BRACKETAttach the engine mounting bracket so that the arrow mark
on the mounting stopper is in the direction as shown in the
illustration.
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II-20ENGINE - Camshaft Oil Seals
CAMSHAFT OIL SEALS
RElVjOVAL AND INSTALLATION
MllZA-B
Pre-removal and Post-installation Operationl Removal and Installation of Timing Belt(Refer to P.l l-26.)l Removal and Installation of Intake Manifold(Refer to GROUP 15 - Intake Manifold.)3Nm
2.2 ftlbs.
3Nm
2.2 f’tlbs.
$1(Refer to GROUP 13 - Engine Control.)3Nm
90 Nm65 ft.lbs.
Removal steps
1. Center cover (front bank)
2. Connection for spark plug cables
3. Connection for breather hose
4. Connection for PCV hose
l *5. Rocker cover** l *6. Camshaft sprocketa* I)* 7. Camshaft oil seals
io01 NO040
01 NO042
1.4 in.) 4(.4 in.)
OlA0047
Sealant: 3M ATD PartNo. 8660 or equivalent
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ENGINE - Camshaft Oil SealsII-21
r
CamshaftOlM0032
Rear bank6
OlL105C(1) Only
No. 5 bolt in the rear-bank differs from other bolts
in length.
Rear bank No. 5 bolt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 mm (.79 in.)
Except rear bank No. 5 bolt
_................... 10 mm (.39 in.)
(2) Bolts are color-coded for the front and rear banks as
follows:
Front bank. . . . . . . . . . . . . . . . . .._....___.._______....__.._..._..... I.........Black
Rearbank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Green(3) When the rocker cover gasket has been replaced,
tighten bolts in this order and then, retighten bolts 1 to 6
to 4 Nm (2.9 ft.lbs.).
1 TSB RevisionSERVICE POINTS OF REMOVALMllZBAG
6. REMOVAL OF CAMSHAFT SPROCKET
Using a wrench at the hexagonal part of the camshaft (to
prevent the crankshaft from turning), loosen the camshaft
sprocket bolt.
CautionDo not hold the camshaft sprocket with a tool, or a
damaged sprocket could result.7. REMOVAL OF CAMSHAFT OIL SEAL
(1) Cut out a portion in the camshaft oil seal lip.
\
(2)Cover the tip of a screwdriver with a cloth and apply it to
the cutout in the oil seal to pry off the oil seal.
Caution
Use care not to damage the camshaft and cylinder
head.SERVICE POINTS OF INSTALLATION
MllZDAI7. INSTALLATION OF CAMSHAFT OIL SEAL
(1) Apply a small amount of engine oil to the oil seal lip.
(2) Using the special tool, insert the oil seal.
6. INSTALLATION OF CAMSHAFT SPROCKET
Using a wrench at the hexagonal part of the camshaft (to
prevent the crankshaft from turning), tighten the camshaft
sprocket bolt.
CautionDo not hold the camshaft sprocket with a tool, or a
damaged sprocket could result.5. INSTALLATION OF ROCKER COVER
Tighten the rocker cover bolts in the order shown in the
illustration.
NOTE’

II-22ENGINE - Oil Pan and Oil Screen
OIL PAN AND OIL SCREENREMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
Draining and Refilling
l Engine Oil(Refer to GROUP 00 -Maintenance Service.)Removal and Installationl Front Air Dam (Refer to GROUP 51 - Aero Parts.)l Under Cover
,
(Refer to GROUP 22, 23 -Transfer Assembly.)
13 NmPI, ll.r
wOlLO156
Sealant: MITSUBISHI GENUINE Part
No. MD9971 10 or equivalent
9Nm- . .. .
60-70Nm -43 - 51 ft.lbs.
MllHA--
,9Nm7 ft.lbs.
26 ft.lbs.6Nm4ft.lbs.7
lt.lbS.
Removal steps
1. Left member7 Ctclrtny
3. Transaxle stay (front)4. Transaxle stay (rear) 5. Bell housing cover6. Connection of oil return pipes60-70
Nm_ .43 - 51 ftms.
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7. Oil pan8. Oil screen^.L^^“1 wu06
1