1991 MITSUBISHI 3000GT check engine

11-48ENGINE - Piston and Connecting Rod
Side railNo.1
spacer slotrail
6ENO41
7EN0032
Cylindcnumbe
Stopper notch4. INSTALLATION OF PISTON, CONNECTING ROD~
ASSEMBLY
(1) Liberally coat engine oil on the circumference of the
piston, piston ring, and oil ring.
d
(2) Arrange the piston ring and oil ring gaps (side rail and
spacer) as shown in the illustration.
(3) Rotate crankshaft so that crank pin is on center of
cylinder bore.
(4) Use suitable thread protectors on connecting rod bolts
before inserting piston and connecting rod assembly
into cylinder block. Care must be taken not to nick crank
pin.(5) Using a suitable piston ring compressor tool, install
piston and connecting rod assembly into cylinder block.
Caution
Insert the pistons so that the front marks (arrows)on the piston tops point toward the front of the
engine (timing belt side).
2. INSTALLATION OF CONNECTING ROD CAP
(1) Install the connecting rod, aligning it with the mark
made or the connecting rod cap during disassembly.
When the connecting rod being installed is new and has
no alignment mark, install it so that the notches in the
connecting rod and cap are on the same side, as
illustrated.
‘d(2) Check the connecting rod big end thrust clearance.
Standard value: 0.10
- 0.25 mm (.0039 -‘.0098 in.)
Limit: 0.4 mm
(-016 in.)
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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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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

11-54ENGINE - Cylinder Block
I
$jA A@/
,12 mm (.47 in.)
I
t+ ‘: ;I 2 Center -
Thrust
direction
-point7EN268
(2) Using a cylinder gauge, measure the inside diameter and
roundness of the cylinder. If excessively worn, repair (over~
size) the cylinder and replace the piston and piston rings.The measurement points are shown in the illustration.
)d
BORING THE CYLINDERMllVEEB
(1) Based on the largest cylinder bore, determine the over
sized piston to be used.
(2) Measure with the outside diameter of the piston as the
datum measurement points.
NOTE
There are four sizes of oversize piston -0.25 mm (.OlO in.),
0.50 mm
(.020 in.), 0.75 mm (.030 in.), 1.00 mm (.039 in.).
(3) Calculate the reground bore size based on the measured.value of the outside piston diameter.
NOTEBore size = outside piston diameter + 0.03 to 0.05 mm
(.0012 to .0020 in.) (gap between cylinder and piston) - 0.02mm (0008 in.) (honing amount)
(4) Hone each of the cylinders to the calculated measurement.
CautionTo prevent distortion resulting from the temperature‘drise during reboring, bore the cylinder holes in the
cylinder numbers sequence.
(5) Hone the cylinders, finishing them to the proper dimension(outside piston diameter + gap with cylinder).
(6) Check the gap between the piston and cylinder.
Standard value: 0.03
- 0.05 mm (.0012 - .0020 in.)
SERWCE POINT OF INSTALLATIONMllVDAL
5. INSTALLATION OF DETONATION SENSOR BRACKET
Check that the bracket is in intimate contact with the
cylinder block boss and tighten to specified torque in the
order shown.
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ENGINE - Engine Oil Cooler
ENGINE OIL COOLER
REMOVAL AND INSTALLATION
11-55
MllMA-.4Nm
2.9 ft.lbs.40-45
Nrh
29 - 33 ft.lbs.Removal steps
1.Front splash shield extensionl *2. Engine oil feed hose3.Engine oil return hose
4*4. Engine oil return tube5. Engine oil cooler
12Nm
9 ft.lbs.5
02FOOOi
SERVICE POINTS OF REMOVALMllMBAC
2.REMOVAL OF ENGINE .OIL FEED HOSE / 4. ENGINE OIL
RETURN TUBE
CautionBe sure to hold the weld nut of the oil cooler while
loosening the eye bolt.
INSPECTIONMllMCAC
l
Check the engine oil cooler fins for bends, breaks or plugs.l Check the engine oil cooler hoses for cracks, damage,
clogging or deterioration.l Check the gaskets for damage or deformation.
l Check the eye bolts for clogging or deformation.
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FUEL
SYSTEM
CONTENTSM13AA- _
CRUISE CONTROL SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . .158SPECIFICATIONS. . . . . . . .._._....................................................155
CRUISE CONTROL SYSTEM*................................................185
SERVICE ADJUSTMENT PROCEDURES............................178
Cruise Control Cables Inspection and Adjustment........178Cruise Control SystemInspection....................................179individual Parts Inspection....................................................181
SPECIAL TOOLS........................................................................159
SPECIFICATIONS....................................................................158
General Specifications........................................................158Service Specifications........................................................158
TROUBLESHOOTING............................................................159
Check Chart............................................................................163Harness and Components Layout....................................176Preliminary Inspection........................................................159Self-diagnosis Checking........................................................172Troubleshooting Quick Reference Chart............................159
ENGINE CONTROL............................................155
ENGINE CONTROL................................................................157
SERVICE ADJUSTMENT PROCEDURES............................156
Accelerator Cable Inspection and Adjustment................156Accelerator Switch Inspection and Adjustment................156
Service Specifications........................................................
155
TROUBLESHOOTING............................................................
155
Accelerator Cable and Accelerator Pedal........................155
FUEL SYSTEM....................................................3
DETONATION SENSOR........................................................154
FUEL FILTER............................................................................
153
FUEL LINE AND VAPOR LINE................................................151
FUEL PUMP AND FUEL GAUGE UNIT ASSEMBLYAND OVERFILL LIMITER (TWO-WAY VALVE)................149
FUEL TANK.................................................................................146
GENERAL INFORMATION
....................................................
3
MPI System Diagram............................................................3
INJECTOR................................................................................141
ON-VEHICLE INSPECTION OF MPI COMPONENTS........36
Active Exhaust Control Unit ............................130Air Conditioner Switch and Power Relay............................82Air Flow Sensor....................................................................54Anti-lock Brake Signal ........................................133Barometric Pressure Sensor................................................60CONTINUED ON NEXT PAGE
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
(1)A Supplemental Restraint System (SRS), which uses a driver-side air bag, has been installed in the 3000GT.(2)The SRS includes the following components: impact sensors, SRS diagnosis unit: SRS warning light, air bagmodule, clock spring, interconnecting wiring. Other SRS-related components (that may have to be
removed/installed in connection with SRS service or maintenance) are indicated in the table of contents byan asterisk (*).
WARNING!(I)Improper service or maintenance of any component of the SRS, or any SRS-related component, can lead to
personal injury or death to service personnel (from inadvertent firing of the air bag) or to the driver (from
rendering the SRS inoperative).
(2) Service or maintenance of any SRS component or SRS-related component must be performed only at anauthorized MITSUBISHI dealer.
(3) MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP
528 -Supplemental Restraint System (SRS), before beginning any service or maintenance of any component of theSRS or any SRS-related component.

13-2
Boost Meter ........................................................128Components Inspection Procedure....................................40
Components Location........................................................36
Crank Angle Sensor
............................................................72Detonation Sensor................................................................84EGR Control Solenoid Valve
........................................121
EGR Temperature Sensor ............................92ElectricalLoad Switch........................................................86Engine and Transaxle Total Control Signal ............135Engine Control Unit Power Ground....................................44Engine Coolant Temperature Sensor................................62Fuel Pressure Control Valve ............................123Fuel Pressure Test................................................................138Fuel Pump ....................................................45Fuel Pump ............................................................48
Fuel Pump Operation Check................................................137Fuel Pump Relay No. 2........................................................53Fuel Pump Resistor............................................................53
Idle Position Switch............................................................68Idle Speed Control Servo (Stepper Motor Type)............1 IOIgnition Coil and Power Transistor....................................115Ignition Switch-ST and Inhibitor Switch ................76Ignition Switch-ST ................................................75Induction Control Valve Position Sensor
........................................................................90
Injectors........................................................101Injectors................................................................105Intake Air Temperature Sensor............................................57Muffler Mode Changeover Switch ....................88Oxygen Sensor ............................................
94
Oxygen Sensor ....................................................98
Power Steering Oil Pressure Switch................................80Power Supply and Ignition Switch-IG................................41
Purge Control Solenord Valve............................................1 19Release of Residual Pressure from High
Pressure Fuel Hose............................................................137Throttle Position Sensor....................................................65Top Dead Center Sensor....................................................70Variable Induction Control Servo (DC Motor)
........................................................................131Vehicle Speed Sensor........................................................78Waste Gate Control Solenoid Valve ................126
SERVICE ADJUSTMENT PROCEDURES............................31
Adjustment of Fixed SAS....................................................35Adjustment of Idle Position Switch and
Throttle Position Sensor (TPS)............................................33Basic Idle Speed Adjustment............................................31Throttle Body (Throttle Valve Area) Cleaning....................33
SPECIAL TOOLS........................................................................8
SPECIFICATIONS
....................................................................6
General Specifications........................................................6Sealant....................................................................................7Service Specifications........................................................7
THROlTLE BODY....................................................................143
TROUBLESHOOTING............................................................9
Check Chart Classified by Problem Symptoms................16Circuit Diagram....................................................................18Engine Warning Light (Malfunction Indicator Light)........11Explanation and Cautions about Harness Check............10Explanation of Troubleshooting Procedures....................9Fuel Tank and Fuel Line........................................................30
Problem Symptoms Table (For Your Information)............17Self-diagnosis........................................................................12)
I

FUEL SYSTEM - Troubleshooting13-9
START1
1. Verification of trouble symptomI
2. Reading of self-diagnosis code
3. Estimation of the causes of trouble and
setting of check items
\1
4. Inspection of engine control unit input/
output signals
\1
5. Inspection of MPI system component
LL
6. Inspection of individual MPI system
components
7. Re-inspection and repair of trouble
symptom
8. Verification and prevention of
reoccur-
TROUBLESHO.OTlNGMlBEBBS
EXPLANATION OF TROUBLESHOOTING PROCE-
DURES
Effective troubleshooting procedures for MPI system problems
are given below.1. Verification of trouble symptom
lReproduce trouble symptom and verify the characteris-
tics of the trouble and the conditions (engine condition,driving conditions, etc.) under which it is produced.
2. Reading of self-diagnosis code
l Read self-diagnosis code and if a malfunction code is
output, locate and correct the trouble referring to the
diagnosis chart.3. Estimation of the causes of trouble and setting of check
items
lReferring to the Check Chart, verify the check items andchecking order for the trouble symptom.
4. Inspection of engine control unit input/output signals
l Using the multi-use tester or oscilloscope, check the
engine control unit input/output signals.
l If the signals are normal, judge the sensor input/
actuator control as normal and proceed to check the
input/output signals of the next check item.
5. Inspection of MPI system component harness
l If the engine control unit input/output signals are
abnormal, check the MPI system component body
harness and repair as necessary.
lAfter repair, check the engine control unit input/output
signals again. If they are normal, proceed to check theinput/output signals of the next check item.
6. Inspection of individual MPI system components
lIf the body harness is normal but the engine control unit
input/output signals are abnormal, check individual MPI
system components and repair or replace as necessary.l After repair or replacement, check the engine control
unit input/output signals again. If they are normal,
proceed to check the input/output signals of the next
check item.7. Re-inspection and repair of trouble symptom
l If the harness inspection and individual component
inspection results are normal but the engine control unitinput/output signals are abnormal, re-examine the
causes of trouble referring to the troubleshooting hintsand the checks and repairs included in other groups.
8. Verification and prevention of reoccurrence after repair
lPerform tests to see if the same problems occur againand make sure that the same problems will not be
repeated.
lRemove the true causes of the trouble to prevent its
reoccurrence.
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