cooling MITSUBISHI 3000GT 1991 User Guide

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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FUEL SYSTEM - On-vehicle .lnspection of MPI Components13-111
INSPECTIONUsing Multi-use Tester
FunctionItem No. Data display
Data reading 45
Stepper
1
motor steps
~
Check condition
l Engine coolant tem-
perature: 80 to 95°C
(176 to 205°F)
0 Lamps, electric cooling
fan, accessory units:
All OFFl Transaxle: Neutral(P range for vehiclewith AA>l Steering wheel: Neutrall Idle position switch: ON(compressor clutch
to be ON if air condi-
tioner switch is ON)l Engine: idling
Load stateStandard value
;;rnditioner switch:2 - 12 stp&conditioner switch:
25 - 65 stp
l $irNconditioner switch:15 - 63 stp0 Selector lever:Shift to D range
NOTEWhen the vehicle is new [within initial operation of about 500 km (300 miles)], the stepper motor steps may be about 30steps more than standard.
CautionWhen the selector lever is shifted to the “D”range, the brakes must be used to prevent the vehicle frommovingforward.
03A020
Using Oscilloscope(1) Connect the probe to each oscilloscope pick-up point as
shown in the circuit diagram.
(2) Start the engine.
(3) When the air conditioner switch is turned on, the idling
speed increases to operate the idle speed control. Check
the instantaneous waveform.
NOTEKeep in mind that the waveform can be observed only
when idle speed control is in operation.
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COOLINGCONTENTS
M14AA..
ENGINE COOLANT TEMPERATURE GAUGE
UNIT, ENGINE COOLANT TEMPERATURESENSOR AND ENGINE COOLANT
TEMPERATURE SWITCH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.__15
RADIATOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
SERVICE ADJUSTMENT PROCEDURES . . . . . . . .7Cap Pressure Test
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.......7Engine Coolant Concentration Test
. . . . . . . . . . . . . . . .‘7
L,Engine Coolant Leak Check
. . . . . . . . . . . . . . . . . . . . . . . . . . . .7Engine Coolant Replacement
. . . . . . . . . . . . . . . . . . . . . . . .7
SPECIFICATIONS. . . . . . . . . . . . .._.................................General Specifications
. ..___....___._...___.__............Lubricant
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.................._........Sealant and Adhesive
. . . . . . . . . . . . . . . . .._...........Service Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . .
THERMOSTAT. . . ..__......................_.._...................
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._...No Rise in Temperature
Overheat
WATER PUMP, WATER PIPE AND WATER
HOSE. . . . _......_........_ _.._ .._..... . . . . . . . . . . . ._. . . . . . . . . . . . . . . . .
2
2
2
3
2
11
3
13

14-2COOLING - SDecifications
SPECIFICATIONSGENERAL SPECIFICATIONSMMCA..
Items
Cooling method
Radiator
Type
Radiator fan motor
Type
Water pump
Type
Thermostat
Type
Identification markSpecifications
Water-cooled, pressurized, forced circulationwith electrical fan
Pressurized corrugated fin type
Direct current ferrite type
Centrifugal impeller type
Wax type with jiggle valve
76.5 (Stamped on flange)
dSERVICE SPECIFICATIONS
Items
Standard valueSpecifications
Range of coolant antifreeze concentration%30-60
Thermostat
Valve opening temperature of thermostat
“C (“F)
Full-opening temperature of thermostat“C (“F)
Opening pressure of cap high pressure valvekPa (psi)
Therm0 sensor (on radiator) operating temperature

OFF-t ON“C (“F)
ON -+ OFF“C (“F) condenser fan-Vehicles with air conditioner>
OFF-ON“C (“F)
ON + OFF“C (“F)
Limit
76.5 (170)
90
(I 94) or more
75-105(11-15)81-89
(178- 192)77(171)orless
91-99
(196-210.)
87 (189) or less
Opening pressure cap high pressure valve
kPa (psi)65 (9.2)LUBRICANT
MlQCD- -
ItemSpecified lubricantQuantity
Engine coolantlit. (qts.)High quality ethylene glycol8.0 (8.5).
antifreeze coolant
‘d
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COOLING - Specifications / Troubleshooting
SEALANT AND ADHESIVE14-3
MMCE- -
/
id
ItemsSpecified sealants and adhesive/
Engine coolant temperature gauge unit
Engine coolant temperature sensor (Engine control)
Engine coolant temperature sensor (Air conditioner)3M Nut Locking Part No. 4171
TROUBLESHOOTING
L
MllEAAL
Symptom
OverheatProbable cause
Insufficient engine coolant
Too high an anti-freeze concentration
Inoperative electric cooling fan
Faulty thermosensor
Faulty electrical motor
Faulty radiator fan relayRemedy
Replenish
Correct anti-freeze concentration
Replace
Damaged or blocked (insufficiently ventilated)
radiator finsCorrect
Water leaks
Damaged radiator core joint
Corroded or cracked hoses
(radiator hose, heater hose, etc.)
Faulty cap valve or setting of spring
Cracked thermostat housing
Loose water pump mounting bolt or leaking
gasket
Replace
Loose bolt or leaking gasket in water outlet
I
Correct or replacefitting
Loose bolt or leaking gasket in water inletfitting
Loose thermostat housing bolts or leakingfrom gasket
Retorque bolts or replace gasket
Faulty automatic transaxle oil cooler operation
Blocked or collapsed hose and pipeReplace
Loose hose and pipe connectionCorrect
Faulty thermostat operationReplace
Faulty water pump operationReplace
Water passage clogged with slime or rust depositClean
or foreign substance
No rise in temperature
Faulty thermostatReplace
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14-4COOLING - Troubleshooting
CIRCUIT DIAGRAM
FUSIBL
RADIATOR
FAN ASSEMBLY
(RADIATOR
,
FAN MOTOR>r{
!&w
F
A-04X ,---LINK0
J
0A
j
IGNITION
J/B
lxI
ti
51.: ,A-07X
J1
>II
ticpLi6
m
R&
b3
,2L-R1
RADIATOR FAN ASSEMBLYL!a ml
T
X35-AC-NWOl-NY
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COOLING - Troubleshootina14-5
i
L
@2L-R
:---I
I
I
I
I
III1 nI
I
1 6IIIII
I
I
I
I
I
I
I
I
ii
II
! cI1
I--@
G-B
FUSIBLELINK@
_------ __._ -_--
L-
AIR CONDITIONER
COMPRESSOR LOCK
CONTROLLERRADIATOR
FAN MOTOR
RELAYCLO)
A-36
A-45
@!A
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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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14-8COOLING - Radiator
RADIATOR
REMOVAL AND INSTALLATIONM14QA..
Removal steps of radiator
1. Drain plug2. Cap3. Overflow tube
4. Water level sensor connector
5. Reserve tank
6. Radiator upper hose
7. Radiator lower hose
8. Automatic transaxle oil cooler hoses
9. Condenser fan motor connector
10. Condenser fan motor assembly

** 11. Radiator fan motor connector
12. Connection of therm0 sensor(For radiator fan)13. Connection of therm0 sensor(For condenser fan)
14. Radiator fan motor assembly
15. Upper insulator
16. Radiator assembly
17. Lower insulator
Removal steps of radiator fan motor assembly
1. Drain plug2. Cap
6. Radiator upper hose
9. Condenser fan motor connector

10. Condenser fan motor assembly

l * 11. Radiator fan motor connector12. Connection of therm0 sensor(For radiator fan)13. Connection of therm0 sensor
18.
Therm0 sensor (For radiator fan)
19. Therm0 sensor (For condenser fan)
(For condenser fan)
20. Fan
14. Radiator fan motor assembly20. Fan
21. Radiator fan motor21. Radiator fan motor
22. Resistor22. Resistor
23. Shroud23. Shroud
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