1991 MITSUBISHI 3000GT engine

14-6COOLING - Troubleshooting.TROUBLESHOOTING HINTS
1. Neither the radiator fan nor condenser fan
rotate at all.
l Check fusible link No. 5.
2. Only the condenser fan does not operate.
l Check dedicated fuse No. 8.
3. The radiator fan and condenser fan do not
operate in the low speed mode, but operate
otherwise.
(1) The A/C compressor magnet clutch does not
enter the “ON” state.
l Check whether the output of the auto
compressor control unit is available.
NOTEFor troubleshooting of the air conditioner
control unit, refer to GROUP 55.
(2) The A/C compressor magnet clutch enters
the “ON” state.
l Check the resistor.
Fan Operating Model Check the radiator fan motor relay (LO)
and condenser fan motor relay (LO).
l Check the therm0 sensor (for radiator
fan).
(3) The radiator fan does not rotate when the ailconditioner switch is turned ON.
l Check the radiator fan motor control
relay.4. The radiator fan and condenser fan do not
operate in the high speed mode, but operate
otherwise.l Check the therm0 sensor (for condenser
fan).
lCheck the radiator fan motor relay (HI) and
condenser fan motor relay (HI).Air
conditionerswitch
Switch conditionsTherm0 sensor
For radiator fan
For condenser fan
ON at 85
k 4°C
ON at 95 t 4°C
(185 f 7°F) or more(203 + 7°F) or more
OFF at 77°C (171°F)
OFF at 87°C (189°F)or less
or lessEngine coolant
temperature switch
(for air conditioner
cut-off) OFF at 115
+3°C (239 2 5°F) or
over, ON at 108°C
(226°F) or lessFan revolving operation
conditionCondenser fan motor
Condenser fan motorRadiator fan motor
operates
In HIGH only
when it receives input
from condenser fan
motor relay (HI) and
U-0).I/I/
OFF
OFF
OFFOFF
IOFFIOFF
ONLOWOFF
ON
HIGHLOW
OFF
OFFLOWLOW
OFF
ONON
LOWLOW
ON
HIGH
ONHIGH
OFF
HIGHLOW
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COOLING - Service Adiustment Procedures.14-7
SERVICE ADJUSTMENT PROCEDURES
ENGINE COOLANT LEAK CHECKMl4FAAF
1. Loosen cap.
2.Confirm that the engine coolant level is up to the filler neck.
3.Install an adapter to the water outlet fitting and apply 160
kPa (23 psi) pressure. Hold pressure for two minutes, while
checking for leakage from the radiator, hose or connec-
tions.
CautionBe sure to completely clean away any moisture from
the places checked.
When the tester is removed, be careful not to spill anyengine coolant from it.
Be careful, when installing and removing the tester andwhen testing, not to deform the water outlet fitting.
4. If there is leakage, repair or replace the appropriate part.
CAP PRESSURE TESTM14FBAH1. Use a special tool to attach the cap to the tester.
2.Increase the pressure until the indicator of the gauge stops
moving.
Limit: 65
kPa (9.2 psi)
Standard value: 75
- 105 kPa (11 - 15 psi)
3:Replace the cap if the reading does not remain at or above
the limit.
NOTEBe sure that the cap is clean before testing, since rust or
other foreign material on the cap seal will cause an
improper indication.
ENGINE COOLANT REPLACEMENTM14FCAGRefer to GROUP 00
- Maintenance Service.
ENGINE COOLANT CONCENTRATION TEST
M14FDALRefer to GROUP 00
- Selection of Coolant.
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14-10COOLING - Radiator
r-----I
113
EY
4 :
2 :
i.-.-..i
0312161908
Ionnector04FOOO8
RADIATOR FAN MOTOR RELAY INSPECTION
(1) Remove radiator fan motor relay from the relay box located
at the right side in the engine compartment.
Ll(2) Check for continuity between the terminals when the
battery power-supply is applied to terminal
0, and terminal@ is grounded.
When current
flowsBetweenterminals 1
- 3Continuity
When nocurrent flowsBetweenterminals 1 - 3No continuity
Betweenterminals 2 - 4Continuity
SERVICE POINT OF INSTALLATIONM14QDAH
11. CONNECTION OF RADIATOR FAN MOTOR CONNEC-
TORConnect the radiator fan motor connector to the body
harness. Then, insert into the shroud hole and fix securely.
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COOLING - Water Pump, Water Pipe and Water Hose
WATER PUMP, WATER PIPE AND WATER HOSE
14-13
M14MB-B
/REMOVAL AND INSTALLATION
Pre-removal and Post-installation
Operation
l Draining and Supplying of the Engine Coolant
(Refer to GROUP 00 - Maintenance Service.)l Removal and Installation of Power Transistor
Unit and Ignition Coil
(Refer to GROUP 16 - Engine Electrical)l Removal and lnstallatlon of Timing Belt
(Refer to GROUP 11 -Timing Belt)17-20 Nm17-20 Nm
12-14ft.lbs.
1
12-15Nm9-11 ft.1bs.q
Removal steps
1. Water pump
2. Gasket
3. Air hose A
4. Air intake hose A
5. Air intake hose B
6. Air intake hose C
7. Air intake hose
8. Connection of radiator upper hose
9. Connection of water hose
IO. Water outlet fitting11. Gasket
12. Connection of harness
13. Connection of heater hose
14. Connection of water hose A
15. Connection of water hose
16. Connection of water hose
17. Connection of radiator lower hose
18. Connection of water hose
19. Thermostat housing
20. Gasket21.
Her water pipe22. O-ringOlFOO51
Installation steps
2. Gasket** 1. Water pumpI)+ 22. O-ring
l * 21. Inlet water pipe
20. Gasket
19. Thermostat housing18. Connection of water hose 17. Connection of radiator lower hose16. Connection of water hose
15. Connection of water hose
14. Connection of water hose A
13. Connection of heater h&e
12. Connection of harness11. Gasket10. Water outlet fitting
9. Connection of water hose
8. Connection of radiator upper hose7. Air intake hose l *6. Air Intake hose C **5. Air intake hose B l *4. Air intake hose A
3. Air hose A
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COOLING - Water Pump, Water Pipe and Water Hose
INSPECTION
WATER PUMP
I
MIQMDAOZIf any of the following irregularities are observed, replace the
LJwater pump as an assembly.
(1) Damage or crack on the water pump body
(2) Water leakage. With improper sealing, a water leakage
mark may be observed around hole
@.
,
(.31 x .98)OlLO188
6COO35
Air intake hose BOSFOO23
SERVICE POINTS OF INSTALLATION
1. INSTALLATION OF WATER PUMPM14MEAW
(1) Clean both gasket surfaces of water pump body and
cylinder block.
(2) Install new water pump gasket and water pump
assembly and tighten the bolts.
(3) Water pump installation bolt size are different and
caution must be paid to ensure that they are properly
installed.
22. INSTALLATION OF O-RING / 21. INLET WATER PIPEReplace the O-rings at both ends of the water inlet pipe
with new ones and apply water to the outside of O-rings to
help smooth insertion of the pipe into the water pump,.
thermostat housing.
CautionLJCare must be taken not to permit engine oil or
othergreases to adhere to the O-ring.
6.INSTALLATION OF AIR INTAKE HOSE C / 5. AIR INTAKEHOSE B
/ 4. AIR INTAKE HOSE A
Assemble the air intake hose A with its notches (arrow-
marked) lined up with the
D marks on the air intake hoses
B and C. Insert the hoses into the air intake hose A until
they are bottomed.
Insert the air intake hoses B and C on the turbocharger side
until they are bottomed.
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COOLINGEngine Coolant Temperature Gauge Unit, Engine Coolant- Temperature Sensor and Engine Coolant Temperature Switch14-15
ENGINE COOLANT TEMPERATURE GAUGE UNIT, ENGINE COOLANT
TEMPERATURE SENSOR AND ENGINE COOLANT TEMPERATURE
L,SWITCH
REMOVAL AND INSTALLATIONM140B. -Pre-removal and Post-installation
Operation
l Draining and Supplying of theEngine Coolant(Refer to GROUP 00 - MaintenanceService.)
30 NmOlFOO38
Removal steps
1. Air hose A l +2. Air intake hose A IF*3. Air intake hose B
4. Connection of radiator upper hose
5. Engine coolant temperature gauge unit
6. Engine coolant temperature sensor
(Engine control)7. Engine coolant temperature switch(Air conditioner)
INSPECTIONM140DAM
ENGINE COOLANT TEMPERATURE GAUGE UNITRefer to GROUP 54
- Meters and Gauges.
ENGINE COOLANT TEMPERATURE SENSOR (Engine con-
trol)Refer to GROUP 13
- MPI System Inspection.
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14-16
I
COOLINGEngine Coolant Temperature Gauge Unit, Engine Coolant- Temperature Sensor and Engine Coolant Temperature SwitchI
Air Intake hose B
05FOO2:
ENGINE COOLANT TEMPERATURE SWITCH (Air condition-I
4
(1) Immerse the engine coolant temperature switch in oil and
then heat (by using a gas stove flame or similar method) so
as to increase the oil temperature.
L.2~(2) Check to be sure that the engine coolant temperature
switch is switched OFF when the oil temperature reaches
the standard value.
Standard value: 112
- 118°C (234 - 244°F)
Caution
The oil used above should be engine oil and should be
stirred well while being heated; do not heat more than
necessary.
SERVICE POINTS OF INSTALLATIONM140EAz
3.INSTALLATION OF AIR INTAKE HOSE B / 2. AIR INTAKE
HOSE AB and L. Assemble the air intake hose A with its notches (arrow-
marked) lined up with the
n marks on the air intake hoses
. -dInsert the hoses Into the air intake hose A until they are
bottomed.
Insert the air intake hose B on the turbocharger side until
they are bottomed.
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INTAKE AND EXHAUST -Troubleshooting (Active Exhaust.System)15-5
ACTIVE EXHAUST SYSTEM CIRCUIT CHECK
5= i C-82
-i
@g
0J/S1%
‘I
‘6 c-71
3
1
+RHEOSTATmACTUATOR
1::ASSEMBLYF-29
&$jq
ACTlYEFXoQBIlBZ"NIT
TROUBLESHOOTING HINTSChecking Active Exhaust Control Unit
TerminalNo.Signal
StatusTerminal voltage
1SPORT MODE signal
SPORT MODENot less than IOV
I-2 TTOUR MODE signal
TOUR MODENot less than IOV
Full open posrtion detection srgnalSPORT MODE(Not lesi’than 5V)
Engine control unit output signal
Control unit ground
Control unit groundTOUR MODE, engine speed of not lessthan 3,500 rpm
TOUR MODE, idle
SPORT MODE
At all times
At all
trmesBattery voltage
ov
Battery voltage
ov
Battery voltage
IFull close position detection signalTOUR MODE(Not lesk?than 5V)
I9Intermediate position detection signalAt all timesNot less than 5V
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