wheel MITSUBISHI 3000GT 1991 Owner's Manual
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1991, Model line: 3000GT, Model: MITSUBISHI 3000GT 1991Pages: 1146, PDF Size: 76.68 MB
Page 100 of 1146

II-50ENGINE - Crankshaft, FlYwheel and Drive Plate
\7EN262
7EN261INSPECTION
MllUCHAFLYWHEEL (engine with a manual transaxle)
(I) Make a visual inspection of the clutch disc. If stepped wear, :streaking, or seizure are apparent, replace it.\J(2) If flywheel run out exceeds the limit, replace it.
Limit: 0.13 mm
t.0051 in.)
RING GEAR (engine with a manual transaxle)
When there is wear, cracks, or other damage to the ring gear
teeth, replace the ring gear by the following procedure. Check
the starter motor pinion.
Ring gear replacement procedure:
(1) Tap around the ring gear to loosen and remove it from the
flywheel..
CautionThe ring gear cannot be removed while it is hot.
(2) Heat the ring gear to 300°C (572°F) and install it into the
flywheel.
CRANKSHAFTInspect out-of-roundness and taper of crankshaft journal and
pin.
Limit:Out-of-roundness of journal and pin:
LJ
0.003 mm (.00012 in.)Taper of journal and pin: 0.005 mm
(.00020 in.)
OIL CLEARANCE MEASUREMENT
(I) To check the oil clearance, measure the outside diameter of
the crankshaft journal and the crank pin and the inside
diameter of the bearing. The clearance can be obtained by
calculating the difference between the measured outside
and inside diameters.
Standard value: 0.019
- 0.044 mm i.0007 - .0017 in.)
Limit: 0.1 mm
(.004 in.)
(2) If the oil clearance exceeds the limit, replace the bearing,
and crankshaft if necessary.
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Page 101 of 1146

ENGINE - Crankshaft. Flvwheel and Drive Plate11-51
id
PLASTIGAGE METHODMllUlAA
Plastigage may be used to measure the clearance.
(1) Remove oil and grease and any other dirt from bearings and
journals.(2) Cut plastigage to the same length as the width of the
bearing and place it in parallel with the journal, off oil holes.
(3) Install the crankshaft, bearings and caps and tighten them
to the specified torques. During this operation, do NOT turn
the crankshaft. Remove the caps. Measure the width-of the
plastigage at the widest part by using a scale printed on the
plastigage sleeve.
If the clearance exceeds the repair limit, the bearing should
be replaced.
Should the standard clearance not be obtained even after
bearing replacement, replace the crankshaft.
SERVICE POINTS OF INSTALLATIONMllUDAM
16. INSTALLATION OF CRANKSHAFT BEARING (UPPER) /
15.10. THRUST BEARING A / 14.11. THRUST BEARING
B
/ 12. CRANKSHAFT BEARING (LOWER)
(1) Classify the crankshaft bearings (upper and lower) by
whether there is an oil groove or not. Then, assemble asshown in the illustration.
(2) Assemble the thrust bearings (A and
B) on the No.3
journal area as shown in the illustration.
CautionInstall them with the groove side facing outward.Crankshaft bearing (upper)
Oil groove
Thrust bearing A
Front of engine(Tlmlng belt side)
EN269
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Page 102 of 1146

11-52ENGINE - Crankshaft, Flywheel and Drive Plate
9. INSTALLATION OF BEARING CAP
(1) Attach the bearing cap on the cylinder block as shown in
the illustration.
(2) Tighten the bearing cap bolts to the specified torque in‘I
the sequence shown in the illustration.
J ~
(3) Check that the crankshaft rotates smoothly.
Cral
Bearing cap
\Bearing cap bolt
Front of engine
(Timing belt side)
7EN270(4) Check the end plate. If it exceeds the limit value,
replace the thrust bearing.
Standard value: 0.05
- 0.25 mm (.0020 - .0098 in.)
Limit: 0.3 mm
(.012 in.)
-rent ofengineTimingIelt side)
8.
LLiN03,ij
1 TSB RevisionINSTALLATION OF BEARING CAP STAY
(1) Apply engine oil to the thread and bearing surface of
each bolt.
(2) Temporarily tighten the bolts on the cylinder block side.(3) Tighten the bolts on the bearing cap side to specified
torque.(4) Finally, tighten the bolts on the cylinder block side to
specified torque.
NOTEThe bearing cap stays A and B differ in shape. Install
correct ones on correct sides.d
Page 103 of 1146

ENGINE -Crankshaft, Flywheel and Drive Plate / Cylinder Block11-53
MB990938-01
CYLINDER BLOCK
REMOVAL AND INSTALLATION7. INSTALLATION OF CRANKSHAFT REAR OIL SEAL
Using the special tool, press-fit a new crankshaft rear oil
seal into the oil seal case.MllVA--
42 Nmftlbs.
1. Roll stopper bracket front2. Roll stopper bracket front (AWD only)3. Roll stopper bracket rear4. Detonation sensorI)* 5. Detonation sensor bracket
6. Cylinder block7EN0319
INSPECTION
CYLINDER BLOCK
MllVCAM(1) Using a straight edge and feeler gauge, measure the
flatness of the cylinder block upper surface.
Standard value: 0.05 mm
(-0020 in.)
Limit: 0.1 mm
(.004 in.)
Grinding limit: 0.2 mm
(.008 in.)
Caution
When the cylinder head is assembled, 0.2 mm (.008 in.)or less of grinding is permissible.
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Page 123 of 1146

FUEL SYSTEM - Troubleshootina13-17
PROBLEM SYMPTOMS TABLE (FOR YOUR INFORMATION)
I;
L
/
L/
Items
Won’t start(no initial combustion)-g Starting problem
2(i;il;i combustion, then
Symptom
The starter is used to crank the engine, but there is no combustion within the
cylinders, and the engine won’t start.
There is combustion within the cylinders, but then the engine soon stalls.(Starting takes a long
time.)Engine won’t start quickly.
Idling instability
(Rough idling)Engine speed doesn’t remain constant; changes during idling.Usually, a judgement can be based upon the movement of the tachometer
>.rpointer, and the vibration transmitted to the steering wheel, shift lever, body, etc.
EThis is called rough idling.
s0
Incorrect idling speedThe engine doesn’t idle at the usual correct speed.
F.-=e-ImpDr;p;ertidling continuityThis non-continuity of idling includes the following elements.(1) Die outPass out. . . . . The engine stalls when the foot is taken from the accelerator pedal,regardless of whether the vehicle is moving or not.(2) Pass out . . The engine stalls when the accelerator pedal is depressed or while
it is being used.
Hesitation
Sag
“Hesitation” is the delay in responseHesitation
of the vehicle speed (engine rpm) thatLNormaloccurs when the accelerator pedal is
depressed in order to accelerate from---
the speed at which the vehicle is nowx\a,r- ,
traveling, or a temporary drop in vehi-g Initialv) accelerator**’ ,8’ /cle speed (engine rpm) during such+ pedal/,’ /
’
acceleration.2 depression
Serious hesitation is called “sag”.2
1“*’.’
/’ ,’I&L-e**’Ii Sag
Poor acceleration
Time1 FU022:
Poor acceleration is inability to obtain an acceleration corresponding to thedegree of throttle opening, even though acceleration is smooth, or the inability toreach maximum speed.
0, Stumble.F
‘iIn
Engine rpm response is delayed when
the accelerator pedal is initially.
depressed for acceleration from thestopped condition.
$Normal
x
:Initial
3acceleratorI//
c
-7
pedal2 depression,#’,
4,/Idling *--’Stumble
Shock
cTime1 FUO22L
The feeling of a comparatively large impact or vibration when the engine isaccelerated or decelerated.
SurgeThis is repeated surging ahead during constant speed travel or during variable
speed travel.
Knocking
A sharp sound like a hammer striking the cylinder walls during driving and which
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Page 137 of 1146

SERVICE ADJUSTMENT PROCEDURES
MlBFHSU
BASIC IDLE SPEED ADJUSTMENT
NOTE(1) The basic idle speed has been factory-adjusted with the
speed adjusting screw (SAS) and does not normally require
adjustment.(2) If the adjustment is required, first check that the ignition
plug, injector,
ISC servo, and compression pressure are
normal.
(1) Before starting the inspection and adjustment procedures,set the vehicle in the following conditions:
l
Engine coolant temperature: 80 to 95°C (176 to 205°F)l Lights, electric cooling fan, accessories: OFF
lTransaxle: Neutral (P range on vehicles with automatic
transaxle)l Steering wheel: Straightforward position
(2) When using the multi-use tester, connect it to the diagnosis
connector.
NOTEThe connection of the multi-use tester grounds the
self-
diagnosis/data transmission selector terminal.
(3) When not using the multi-use tester, proceed as follows:
@) Insert a paper clip into the l-pin blue connector as
shown in the illustration. FUEL SYSTEM
- Service Adjustment Procedurks13-31
i
@ Connect a primary-voltage-detecting tachometer to the
paper clip.
NOTEThe
tacho/neter should read l/3 of the actual engine
speed. This means that the actual engine speed is thetachometer reading multiplied by 3.
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Page 161 of 1146

FUEL SYSTEM - On-vehicle Inspection of MPI Components13-55
INSPECTIONUsing Multi-use Tester
Function
Data readingtern No. Data display
12Sensor airvolume(frequency)
Check conditionEngine stateStandard value
l Engine coolant tem-
700 rpm (Idle)25-50 Hzperature: 80 to 95°C
(176 to 205°F)2,000 rpm70-IOOHzl Lights and accessories:OFFRacingFrequency increasesl Transaxle: Neutralwith racing(P range for vehiclewith AIT)l Steering wheel: Neutral
NOTEWhen the vehicle is new [within initial operation of about 500 km (300 miles)], the air flow sensor output frequency maybe about 10% higher.
Function
Data listItem No. Data displayCheck conditionsEngine conditionsStandard value
34Reset signall Engine warm up700 rpm (Idle)ON
condition2,000 rpmOFF
L;
FunctionItem No. Data display
Data list37Volumetric
efficiencyCheck conditionEngine stateStandard valuel Engine coolant tem-700 rpm (Idle)20-35%
perature: 80 to 95°C
(176 to 205°F)
l Lights, electric cooling2,000 rpm15-30%
fan and accessory opera-tion: OFFl Transaxle: NeutralRacingFrequency increases
(P range for vehiclewith racingwith &T)
l Steering wheel: Neutral
Using Oscilloscope(1) Run the engine at idle speed.
(2) Connect the probe to the oscilloscope pick-up point as
shown in the circuit diagram, and check the waveform.
Regular waveform
03A0203
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Page 187 of 1146

FUEL SYSTEM- On-vehicle Inspection of MPI Components13-81
INSPECTIONUsing Multi-use Tester
Function
Data readingItem No. Data displayCheck conditionSteering wheelNormal indication
27Switch stateEngine: IdlingSteering wheel neutralOFFposition (wheels
straight-ahead direction)
Steering wheel half turn
ON
Checking Oil Pressure
Steering wheelOil pump delivery pressure (ref. value)
Straight forward700 - 1,200 kPa (100 - 171 psi)
Turned1,500
- 2,000 kPa (213 - 284 psi)
HARNESS INSPECTION
i1
@ Harness side
connector
Measure the power supply voltage.
SENSOR INSPECTIONRefer to GROUP 37
- Service Adjustment Procedures.
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Page 208 of 1146

13-102FUEL SYSTEM - On-vehicle Inspection of MPI Components
TROUBLESHOOTING HINTSHint 1: If the engine is hard to start when hot, check fuel pressure and check the injector for leaks.
Hint 2:If the injector does not when the engine that is hard to start is cranked, the following as well as the
Iinjector itself may be responsible.
(1) Faulty power supply circuit to the engine control unit, faulty ground circuit
\-J
-(2) Faulty control relay
Hint 3:(3) Faulty crank angle sensor, top dead center sensor
If there is any cylinder whose idle state remains unchanged when the fuel injection of injectors is cut
one after another during idling, make following checks about such cylinder.
(1) Injector and harness check
(2) Ignition plug and high tension cable check
(3) Compression pressure check
Hint 4: If the injector harness and individual part checks have resulted normal but the injector drive time is
out of specification, the following troubles are suspected.
(1)Poor combustion in the cylinder (faulty ignition plug, ignition coil, compression pressure, etc.)
(2) Loose EGR valve seating
(3) High engine resistance
INSPECTIONUsing Multi-use Tester
FunctionItem No. Data displayCheck conditionCoolant temperatureStandard valueData reading 41
Drive time”’Engine: Cranking0°C (32”F)*zApprox. 17 ms
20°C (68°F)Approx. 46 ms
8O"C(176"F)Approx. 11 ms
Function
Data readingItem No.Data display
41Drive time*3l Engine coolant tem-perature: 80 to 95°C700 rpm (Idle)2.4-3.0 ms
(176 to 205°F)2,000 rpm2.0-2.6
msl Lamps, electric coolingfan, accessory units:When sharp racing isTo increaseAll OFF
madel Transaxle: Neutral
(P range for vehicle
with A/T)l Steering wheel: Neutral
Check conditionEngine stateStandard value ,
.---NOTE“I : The injector drive time refers to when the supply voltage is 11 V and the cranking speed is less than 250 rpm.*2: When coolant temperature is lower than 0°C (32°F). injection ismade by four-cylinders.---simultaneously.
“3: When the vehicle is new [within initial operation of about 500 km (300 miles)], the injector drive time may be about
10% longer.
Function
Actuator testItem No.
Drive content
Check conditionNormal state
01No. 1 injector shut offEngine: Idling afterIdle state to change
02No. 2 injector shut offwarm-up
(Shut off the injectorsfurther (becoming less
in sequence during afterstable or stalling)
03
No. 3 injector shut offengine warm-up, check
04No. 4 injector shut offthe idling condition)
05No. 5 injector shut off
06No. 6 injector shut off
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Page 212 of 1146

13-106FUEL SYSTEM - On-vehicle Inspection of MPI Components
INSPECTION
Using Multi-use Tester
FunctionItem No.Data displayCheck conditionCoolant temperatureStandard value‘L,,,J
DataDrive time*’0°C (32’F)*’readingiRea:bankiEngine: CrankingApprox. 53 ms
(FronT7bank)20°C (68°F)
Approx. 29 ms
80°C (176°F)Approx. 7 ms
FunctionItem No.
Data displayCheck conditionEngine stateStandard value
Datareading(Reaebank)Drive time*3l Engine coolant tem-700 rpm (Idle)1.9 - 2.5 ms
perature: 80 to 95°C
(Front7banki(176 to 205°F)2,000 rpm1.6 - 2.2 ms
l Lamps, electric coolingfan, accessory units:To increase
All OFFWhen sharp racing is
made
l Transaxle: Neutral(P range for vehicle
with A/T)
l Steering wheel: Neutral
NOTE“I : The injector drive time refers to when the supply voltage is 11 V and the cranking speed is less than 250 rpm.
“2: When coolant temperature is lower than 0°C (32°F). injection is made by four cylinders simultaneously.
“3: When the vehicle is new [within initial operation of about 500 km (300 miles)], the injector drive time may be about
10% longer.
Function
Actuator testItem No.
Drive contentCheck conditionNormal state
01No. 1 injector shut offEngine: Idling afterIdle state to changewarm-upfurther (becoming less
02No. 2 injector shut off(Shut off the injectorsstable or stalling)
03in sequence during afterNo. 3 injector shut offengine warm-up, checkthe idling condition)
04No. 4 injector shut off
05
No. 5 injector shut off
06
No. 6 injector shut off
\,iUsing
OscillqscopeI(1) Run the engine at idle speed.
(2) Connect the probe to the oscilloscope pick-up point as
shown in the circuit diagram, and check the waveform at
the drive side of each injector.~
-
LJ
4 AL A: InjectorNormal waveformdrive time03A0209
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