Engine TOYOTA SUPRA 1995 Service User Guide

Go to step
Check and replace ECM.
Check voltage between terminal A/C of ECM and body ground.
Check voltage between terminal MGC of A/C amplifier connector and
body ground.
Magnetic ClutchVoltage
ON
OFF
Below 1 V
4 ± 6 V
1. Remove A/C amplifier with connectors still con
nected.
2. Start the engine.
Check voltage between terminal A/C IN of A/C amplifi-
er connector and body ground when magnetic clutch is
on and off by A/C switch.
1. Remove the ECM with connectors still con
nected.
2. Turn ignition switch on.
Magnetic ClutchVoltage
ON
OFF
Below 1 V
10 ± 14 V
Check and replace A/C amplifier.
Repair or replace harness or connector.
Check for open and short in harness and connector between A/C am-
plifier and ECM (See page IN±30).
1. Push the A/C switch on.
2. Measure voltage between terminal A/C of the
ECM connector and body ground.
AC±64± AIR CONDITIONING SYSTEMTROUBLESHOOTING

REFRIGERANT SYSTEM INSPECTION WITH MANIFOLD GAUGE SET
This is a method in which the trouble is located by using a manifold gauge set.
(See ªUSE OF MANIFOLD GAUGE SETº on page AC±11)
Read the manifold gauge pressure when the following conditions are established:
(a) Temperature at the air inlet with the switch set at RECIRC is 30±35 °C (86±95 °F)
(b) Engine running at 1,500 rpm
(c) Blower speed control switch set at high
(d) Temperature control set at max. cool
HINT: It should be noted that the gauge indications may vary slightly due to ambient temperature condi-
tions.
1. NORMALLY FUNCTIONING REFRIGERATION SYSTEM
Gauge reading:
Low pressure side:
0.15±0.25 MPa (1.5±2.5 kgf/cm
2)
High pressure side:
1.37±1.57 MPa (14±16 kgf/cm
2)
± AIR CONDITIONING SYSTEMTROUBLESHOOTINGAC±71

6. REFRIGERANT OVERCHARGE OR INSUFFICIENT COOLING OF CONDENSER
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
(1) Clean condenser
(2) Check fan motor
operation
(3) If (1) and (2) are in
normal state, check
amount of refrigerant
Charge proper amount
of refrigerant
Pressure too high on both
low and high pressure
sides

No air bubbles seen
through the sight of glass
even when the engine
rpm is lowered.
Unable to develop
sufficient performance
due to excessive
refrigerant in system

Insufficient cooling of
condenser
Excessive refrigerant in
in cycle " refrigerant
overcharged

Condenser cooling
insufficient " condenser
fins clogged or fan motor
faulty
Condition: Insufficient Cooling
7. AIR PRESENT IN REFRIGERATION SYSTEM
Condition: insufficient cooling
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
(1) Check compressor oil to
see if dirty or insufficient
(2) Evacuate air and charge
new refrigerant
Pressure too high on both
low and high pressure
sides

The low pressure piping is
hot to the touch

Bubbles seen in sight
glass
Air entered in
refrigeration system
Air present in
refrigeration system
NOTE: These gauge indications are shown when the refrigeration
system has been opened and the refrigerant charged without
vacuum purging.

Insufficient vacuum
purging
AC±74± AIR CONDITIONING SYSTEMTROUBLESHOOTING

REFRIGERANT VOLUME
REFRIGERANT VOLUME INSPECTION
1. RUN ENGINE AT APPROX. 1,500 RPM
2. SET TEMPERATURE CONTROL AT MAX. COOL
3. SET BLOWER SWITCH AT ºHIº
4. SET AIR INLET CONTROL AT ºRECIRCº
5. TURN A/C SWITCH ON
6. FULLY OPEN DOORS
7. INSPECT AMOUNT OF REFRIGERANT
Observe the sight glass on the liquid tube.
 Item Symptom Amount of refrigerant Remedy
 
 
 
 
1
 
 
 
 
Bubbles present in sight glass
 
 
 
 
Insufficient*
 
 
 
 
(1) Check for gas leakage with gas leak
tester and repair if necessary
(2) Add refrigerant until bubbles dis±
appear
 
 2
 
 No bubbles present in sight glass
 
 
None, sufficient or too
much 
 Refer to items 3 and 4
 
 
 
 
3
 
 
 
 
No temperature difference between
compressor inlet and outlet
 
 
 
 
Empty or nearly empty
 
 
 
 
(1) Check for gas leakage with gas leak
tester and repair if necessary
(2) Add refrigerant until bubbles disap-
pear
 
 4 
 
Temperature between compressor
inlet and outlet is noticeably different 
 Correct or too much 
 Refer to items 5 and 6
 
 
 
5
 
 
 
Immediately after air conditioning is
turned off, refrigerant in sight glass
stays clear 
 
 
Too much
 
 
 
(1) Discharge refrigerant
(2) Evacuate air and charge proper
amount of purified refrigerant
 
 
 
6
 
 
 
When air conditioning is turned off,
refrigerant foams and then stays
clear 
 
 
Correct
 
 
 
±±
* Bubbles in the sight glass with ambient temperatures higher
than usual can be considered normal if cooling is sufficient.
REFRIGERANT CHARGE VOLUME
Specified amount:
700 + 50 g (24.96 + 1.76 oz.)
AC±76± AIR CONDITIONING SYSTEMREFRIGERANT VOLUME

DRIVE BELT TENSION
DRIVE BELT TENSION INSPECTION
1. INSPECT DRIVE BELT'S INSTALLATION CONDITION
Check that drive belt fits properly in the ribbed grooves.
2. INSPECT DRIVE BELT TENSION
Check that the tension is within A range on the auto tensioner
scale.
If the tension is not within the A range on the scale, replace
the belt with a new one.
HINT: When replacing the drive belt with a new one, the belt's
tension should be within the B range on the belt tensioner
scale.
IDLE±UP SPEED
IDLE UP SPEED INSPECTION
1. WARM UP ENGINE
2. INSPECT IDLE SPEED
Put gear shift in neutral.
2JZ±GE (M/T)
 
Magnetic clutch condition 
Standard idle speed (RPM)
 Not engaged Approx. 700
 Engaged Approx. 900
2JZ±GE (A/T)
 Magnetic clutch condition Standard idle speed (RPM) Not engaged Approx. 700 
 Engaged
 
 Approx. 800
2JZ±GTE
 Magnetic clutch condition Standard idle speed (RPM)
 Not engaged Approx. 650 Engaged Approx. 800
± AIR CONDITIONING SYSTEMDRIVE BELT TENSIONAC±77

AIR CONDITIONING UNIT
AIR CONDITIONING UNIT REMOVAL
1. DISCHARGE REFRIGERANT IN REFRIGERATION
SYSTEM
INSTALLATION HINT: Evacuate air from refrigeration sys-
tem.
Charge system with the refrigerant and inspect for leakage
of refrigerant.
Specified amount:
700 + 50 g (24.96 + 1.76 oz.)
2. DRAIN ENGINE COOLANT FROM RADIATOR AND
ENGINE COOLANT DRAIN COCK
3. REMOVE ENGINE WIRE HARNESS BRACKET
MOUNTING BOLT
4. REMOVE BRAKE TUBE BRACKET MOUNTING BOLTS
FROM DASH PANEL
5. REMOVE WATER HOSE FROM HEATER RADIATOR
6. REMOVE INSULATOR RETAINER
Remove the 2 bolts and the insulator retainer.
7. REMOVE LIQUID TUBE AND SUCTION TUBE
(a) w/ ABS:
Remove the ABS actuator.
(See page BR±44)
(b) Remove the liquid tube and suction tube.
Torque: 10 NVm (100 kgfVcm, 7 ftVlbf)
INSTALLATION HINT: Lubricate the new O±rings with com-
pressor oil and install tubes.
8. REMOVE PLATE COVER
Remove the 2 bolts and the plate cover.
9. REMOVE INSTRUMENT PANEL AND REINFORCEMENT
(See page BO±45) AC±80
± AIR CONDITIONING SYSTEMAIR CONDITIONING UNIT

10. REMOVE HEATER TO REGISTER NO. 3 DUCT
Remove the 3 screws and the heater to register No. 3 duct.
11. REMOVE A/C UNIT
(a) Disconnect connectors from the unit.
(b) Remove the 6 bolts and the A/C unit.
INSTALLATION HINT: Pull the drain hose of the A/C unit for-
ward until the yellow paint on the hose is visible in the engine
compartment.
Insert the drain hose into the engine compartment hose until
the matchmarks are aligned.
± AIR CONDITIONING SYSTEMAIR CONDITIONING UNITAC±81

5. REMOVE AIR MIX SERVOMOTO
(a) Remove the defroster duct.
(b) Remove the 3 screws and the water valve cover.
(c) Disconnect the connector.
(d) Disconnect the control link.
(e) Remove the 2 screws and the air mix servomotor.
6. REMOVE HEATER RADIATOR AND WATER VALVE
(a) Remove the 2 screws and the plate.
(b) Remove the 2 screws and the clamp.
(c) Remove the 3 screws.
(d) Pull out the heater radiator with the water valve.
(e) Remove the 2 screws and water valve from the heater
radiator.
7. REMOVE HEATER AIR DUCT
Remove the 2 screws and the defroster air duct.
8. REMOVE VENT AIR DUCT
(a) Disconnect the control link.
(b) Remove the 2 screws and the vent air duct.
9. REMOVE ENGINE COOLANT TEMPERATURE SENSOR
(a) Disconnect the connector.
(b) After pulling off the clamp, pull out the sensor.
10. REMOVE AIR OUTLET SERVOMOTOR
(a) Disconnect the connector.
(b) Remove the 3 screws and the air outlet servomotor. AC±84
± AIR CONDITIONING SYSTEMAIR CONDITIONING UNIT

AIR CONDITIONING UNIT ASSEMBLY
Assembly is in the reverse order of disassembly.
AIR CONDITIONING UNIT INSTALLATION
Installation is in the reverse order of removal.
COMPRESSOR
ON±VEHICLE INSPECTION
Magnetic Clutch:
(See page AC±62)
Compressor:
1. INSTALL MANIFOLD GAUGE SET
(See page AC±11)
2. START ENGINE
3. INSPECT COMPRESSOR FOR METALLIC SOUND
Check that there is metallic sound from the compressor when
the A/C switch is turned ON.
If a metallic sound is heard, replace the compressor assem-
bly.
4. INSPECT PRESSURE OF REFRIGERATION SYSTEM
See ºRefrigeration System Inspection with Manifold Gauge
Setº on page AC±71.
5. STOP ENGINE
6. INSPECT VISUALLY FOR LEAKAGE OF REFRIGERANT
FROM SAFETY SEAL
If there is any leakage, replace the compressor assembly.
± AIR CONDITIONING SYSTEMAIR CONDITIONING UNITAC±85

COMPRESSOR REMOVAL
1. RUN ENGINE AT IDLE SPEED WITH A/C ON FOR
APPROX. 10 MINUTES
2. STOP ENGINE
3. REMOVE BATTERY
4. DISCHARGE REFRIGERANT IN REFRIGERATION
SYSTEM
5. REMOVE DRIVE BELT
Loosen the drive belt tension by turning the drive belt tension-
er clockwise, and remove the drive belt.
6. REMOVE POWER STEERING PUMP
7. DISCONNECT DISCHARGE HOSE AND SUCTION HOSE
FROM COMPRESSOR
NOTICE: Cap the open fittings immediately to keep mois-
ture out of the system.
8. REMOVE COMPRESSOR
(a) Disconnect connector from compressor.
(b) Remove engine under cover.
(d) Remove the 4 bolts, nut and stud bolt.
(d) Remove the compressor. AC±86
± AIR CONDITIONING SYSTEMCOMPRESSOR