1991 MITSUBISHI 3000GT Catalytic

15-I
I
k..INTAKE AND ~
EXHAUST
=
CONTENTSME.AA- -
ACTIVE EXHAUST SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . .
AIR CLEANER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AIR INTAKE PLENUM . . . . . . . . . . . .
AIR INTAKE PLENUM . . . . . . . . . . . . . . . . . . . .
EXHAUST MANIFOLD . . . .._.._.
EXHAUST MANIFOLD . . . . . . . . . . . . . . . ..__
LEXHAUST PIPE, MAIN MUFFLER ANDCATALYTIC CONVERTER . .EXHAUST PIPE, MAIN MUFFLER AND
CATALYTIC CONVERTER . . . . . . . . . . . . . . . .
INTAKE MANIFOLD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INTERCOOLER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE ADJUSTMENT PROCEDURES. . . . . . . .Air Bypass Valve Inspection
. . . . . . . . . . . . . .._..Intake Manifold VacuumInspection
. . . . . . . . . . . . . . . .Supercharging Pressure Control System
Inspection
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
9
13
14
27
28
30
31
16
11
6
8
8
7Supercharging Pressure Relief Solenoid
ValveInspection
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._........Turbocharger Supercharging Pressure
Inspection
. . . . . . . . . . .._................................._.___.........Variable Induction Control System
Inspection
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.....
SPECIAL TOOL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._____..
SPECIFICATIONS................................................General Specifications
....................................Service Specifications
....................................
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . .._._.._....Abnormal Noise
Exhaust Gas Leakage
TROUBLESHOOTING
(Active Exhaust System)
. . . . . . . . . . . . . . . . . . . . . . ..________....
TURBOCHARGER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TURBOCHARGER(FRONT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TURBOCHARGER (REAR). . . . . . . . . . . . . . . .8
6
4
24
18
21

15-30 INTAKE AND EXHAUST -Exhaust Pipe, Main Muffler and Catalytic Converter
EXHAUST PIPE, MAIN MUFFLER AND CATALYTIC CONVERTER
MlLRA-A
REMOVAL AND INSTALLATION
1. Main muffler and center exhaust50 Nm36
Fbs.
I\
yil / \2: h2yR ‘i”
3. Rubber hangers, ,4. Rubber nanger5. Main muffler6.Mouldings7.Hanger brackets8. Catalytic converter and center
exhaust pipe installation bolts
9.Hanger bracket10.Protector11.Rubber hangers12. Center exhaust pipe13.Gasket
---------179fl
/-r
9 ftlbs./----------------m _
I
!
14. Rubber hangers
15. Hanger bracket
16. Hanger brackets
17. Rear floor heat protector13 Nm
13 Nm
9 ftlbs.9 ft,lbs.5Nm
4 ft.lbs.
35hlm
25 ft.lbs.18. Catalytic converter and front
exhaust pipe installation bolts
19. Catalytic converter
20. Gasket
21. Oxygen sensor connection
22. Self-locking nuts9
ft.lbs.\/23.Rubberhanger24. Front exhaust pipe25.Gasket26.Hangerbracket27. Front floor heat protector
05FOO39
SERVICE POINTS OF REMOVAL
3.4. REMOVAL OF RUBBER HANGER / 5. MAIN MUFFLERSupport with a transmission jack, etc.
INSPECTIONMlSRCAM
l Check the mufflers and pipes for corrosion or damage.
l Check the rubber hangers for deterioration or damage.
l Check for gas leakage from mufflers and pipes.wision
1
L.J

INTAKE AND EXHAUST -Exhaust Pipe, Main Muffler and Catalytic Converter 15-31
- EXHAUST PIPE, MAIN MUFFLER AND CATALYTIC CONVERTER
MlSRA-S
ii REMOVAL AND INSTALLATION31
/
L
LRemoval steps
36ft.lbs.
22013 Nm9 ft.lbs.----
em
/---------6_ 5ftJbs.13 Nm
9 ft.lbs.
1. Main muffler and center
exhaust pipe installation
bolts
2. Protector
l +3. Connection of cable assemblya*4. Rubber hangersa*5. Rubber hangersl *6. Main muffler
7. Gasket8. Mouldings
9. Hanger brackets10. Catalytic converter and center
exhaust pipe installation nuts
11. Hanger bracket
12. Rubber hangers13 Nm
9
ft.lbs.
13. Center exhaust pipe14.Gasket15.Rubber hangers
16.Hanger brackets17.Hanger bracket
18. Rear floor heat
protector
19. Catalytic converter and front
exhaust pipe installation bolts
20.Catalytic converter21.Gasket22.Self-locking nuts23.Rubber hanger
24. Front exhaust pipem
-.Ibs.
25.Gaskets
26.Self-locking nuts
27. Catalytic converter (Right)28.Gasket
29.Hanger bracket
+*l 4130.Oxygen sensor connection31. Heat protector D
32. EGR pipe connection
33.Gasket34. Catalytic converter (Left)
35. Heat protector E
36. Gasket
37. Front floor heat protectorTSB Revision

15-32 INTAKE AND EXHAUST -Exhaust Pipe, Main Muffler and Catalytic Converter
SERVICE POINTS OF REMOVALMlBRBAA
4. 5. REMOVAL OF RUBBER HANGER / 6. MAIN MUFFLERSupport with a transmission jack, etc.
:iJ ~
30. REMOVAL OF OXYGEN SENSORDisconnect the connector of the oxygen sensor, and install
the special tool to the oxygen sensor.
INSPECTIONMlSRCAN
l Check the mufflers and pipes for corrosion or damage.
l Check the rubber hangers for deterioration or damage.
l Check for gas leakage from mufflers and pipes.
lCheck if the main muffler active exhaust system valve can\\be moved smoothly by hand.
SERVICE POINTS OF-INSTALLATIONMllRDAl
30. INSTALLATION OF OXYGEN SENSORUse the special tool to install the oxygen sensor.
3. INSTALLATION OF CABLE ASSEMBLY
Install with the paint mark facing up and adjust the adjusting
nut to obtain the illustrated dimension.
TSB Revision

17-1
EMISSIONCONTROL
.~
CATALYTIC CONVERTER............................:...Inspection
............................................................Removal and Installation
................................
CONTENTSM17.U. -
CRANKCASE EMISSION CONTROL
SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ComponentsLocation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Crankcase Ventilation System Inspection
._..Positive Crankcase Ventilation Valve
. . . . . . . . . . . .
EVAPORATIVE EMISSION CONTROL
SYSTEM................................................................Air Conditioner Switch
....................................Air Flow Sensor, Engine Coolant
Temperature Sensor and Intake Air
Temperature Sensor
........................................Canister
............................................................Components Location
....................................
FuelFiller CapInspection................................OverfillLimiter (Two-way Valve)
....................Purge Control Solenoid Valve
........................Purge Control System Inspection
....................................................Purge Control System Inspection

............................................................Purge Control Valve
........................
PurgePort VacuumCheck................................14
14
14
6
10
10
10
6
10
10
9
7
8
9
9EXHAUST GAS RECIRCULATION
(EGR)
SYSTEM. . . . . ..____._.._........__........_____.........................Air-FuelRatio Control (MPI) System. . . . . . . .
Components Location
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .EGR Control Solenoid Valve
- Non Turbo, Turbo>. . . . . . . . . . . . . . . . . . . .EGR System Inspection
- Non Turbo, Turbo>. . . . . . . . . . . . . . . . . . . .EGR Temperature Sensor
. . . . . . . .EGR Valve - Non Turbo, Turbo>
EGR Valve Control Vacuum Check
- Non Turbo, Turbo>. . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS................................................General Specifications
....................................Service Specifications
....................................
TROUBLESHOOTING. . . . . . . . . . . . . . . . . ..______...............
VACUUM HOSES................................................Inspection
............................................................Installation
........................................................VacuumHosesRouting
....................................
11
14
11
13
12
13
13
12
2
2
22

17-2EMISSION CONTROL - Specifications / Troubleshooting
SPECIFICATIONS
GENERAL SPECIFICATIONSMl’ICA- -\
Items
Crankcase emission control systemSpecifications
Closed type with positive crankcase ventilationvalve
Evaporative emission control systemCanister storage type
Canister
Charcoal type
Purge control solenoid valve
ON/OFF solenoid valve
Exhaust emission control system
Exhaust gas recirculation system
EGR valveVacuum-activated diaphragm type
EGR temperature sensor Thermistor type
EGR control solenoid valve - Non Turbo, Turbo>Duty cycle solenoid valve
Catalytic converter
Monolith type
Location
Under floor
Turbocharger outlet (front bank and rear bank,)
and under floor
SERVICE SPECIFICATIONSMl7CB-.
ItemsSpecifications
Purge control solenoid valve coil resistance
036 - 44 [at 20°C (68”F)I\
EGR temperature sensor resistancekfl60 - 83 [at 50°C (I 22”F)]
11 - 14 [at 100°C (212”F)l
EGR control solenoid valve coil resistance1236 - 44 [at 20°C (68”F)lI
TROUBLESHOOTING
Symptom
Engine will not start
or hard to start
Rough idle or engine
stalls
Probable cause
Vacuum hose disconnected or damaged
The EGR valve is not closed
Malfunction of the purge control solenoid valve
The EGR valve is not closed
Vacuum hose disconnected or damaged
Malfunction of the positive crankcase ventilationvalveRemedy
Repair or replace
Repair or replace
Repair or replace
Repair or replace
Repair or replace
Replace
Malfunction of the purge control systemCheck the system; if there is a
problem, check its component parts
Engine hesitates or3oor acceleration
Zxcessive oil:onsumptron
Malfunction of the exhaust gas recirculation
system
Positive crankcase ventilation line cloggedCheck the system; if there is a
problem, check its component parts
Check positive crankcase
ventila-tion system
Ioor fuel mileageMalfunction of the exhaust gas recirculation
systemTSB RevisionCheck the system; if there is a
problem, check its component parts
d

17-14 EMISSION CONTROL -Exhaust Gas Recirculation (EGR) System / Catalytic Converter
6EM01871
6EM0181(4) Apply a vacuum and check for air-tightness when voltage
applied directly to the EGR control solenoid valve and when
the voltage is discontinued.
Battery voltageResult
When applied
When discontinued
Vacuum is maintained
Vacuum leaks
(5) Measure the resistance between the terminals of the
solenoid valve.
Standard value: 36
- 44 R [at 20°C (68”F)]
AIR-FUEL RATIO CONTROL (MPI) SYSTEMM17ICAJ
lTo inspect the air-fuel ratio control (MPI) system, refer to
GROUP1 3 - Service Adjustment Procedures.
lFor detailed information concerning the illumination pattern
of the malfunction-indicator light and other aspects of the
self-diagnosis function, refer to GROUP 13 -Self-diagnosis.
\.J
CATALYTIC CONVERTERMl7N& -
REMOVAL AND INSTALLATIONRefer to GROUP 15
- Exhaust Pipe, Main Muffler and Catalytic
Converter.
INSPECTIONMl7NCAA
Inspect for damage, cracking or deterioration. Replace if faulty.
Caution1. Operation of any type, including idling, should be
avoided if engine misfiring occurs. Under this conditionthe exhaust system will operate at abnormally high
temperature, which may cause damage to the catalystor underbody parts of the vehicle.
2.Alteration or deterioration of ignition or fuel system, or
any type of operating condition which results in enginemisfiring must be corrected to avoid overheating the
catalytic converters.
3.Proper maintenance and tune up according to manufac-turer’s specifications should be made to correct the
‘bi
conditions as soon as possible.TSB Revision

POWER PLANT MOUNT - Engine Roll Stopper
ENGINE ROLL STOPPER
REMOVAL ANDINSTALLATION
32-5
MJZGF- .
Pre-removal and Post-installationOperationl Removal and Installation of Condenser
Fan Motor Assembly
(Refer to GROUP 55 - Condenser and
Condenser Fan Motor.)
l Removal and installation of Catalytic
Converter (Left)
(Refer to GROUP 15 -Turbocharger.)
45 Nm/33 ft.lbs.
43
- 51 ftlbs.Front stopper bracket removal steps
1. Front roll stopper bracket and engine
connection bolt
2. Front roll stopper bracket installation bolt
3. Front roll stopper bracket
4. Heat protector

50-60 Nm36 - 43 ft.lbs.Rear roll stopper bracket removal steps
5. Air hose A
6. Air intake hose C
l +7. Rear roll stopper bracket and engine
connection bolt
8. Rear roll stopper bracket installation bolt
+* *+9. Rear roll stopper bracketIO. Heat protector OlFOO30
II\ OlFOO4:
SERVICE POINT OF REMOVALM32GEAL
9. REMOVAL OF REAR ROLL STOPPER BRACKET
(1) Slightly raise the rear roll stopper bracket.
(2) Turn the rear roll stopper bracket in the direction shownin the illustration and lift upward to remove.
INSPECTIONM32GCAM3l Check each insulator for cracks or damage.
l Check each bracket for deformation or damage.
9TSB Revision
SERVICE POINTS OF INSTALLATIONM32GJAC
9. INSTALLATION OF REAR ROLL STOPPER BRACKETInstall the rear roll stopper bracket as shown in the
illustration.7. INSTALLATION OF REAR ROLL STOPPER BRACKET
AND ENGINE CONNECTION BOLT
Install the bolt as shown in the illustration.