TOYOTA SUPRA 1995 Service Repair Manual

COMPONENTS FOR REAR TWC
REMOVAL AND INSTALLATION
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GE)EG±173

SERVICE SPECIFICATIONS
TORQUE SPECIFICATIONS
 Part tightened NVm kgfVcm ftVlbf
 EGR valve x Intake air connector 21 210 15
 EGR gas temperature sensor x EGR valve 20 200 14 
 EGR pipe x Cylinder head
 
 27
 
 280
 
 20
 EGR valve x EGR pipe 64 650 47
 No.2 front exhaust pipe (Front TWC) x Exhaust manifold 62 630 46
 Pipe support bracket x Transmission 43 440 32 
 No.2 front exhaust pipe (Front TWC) x Front exhaust pipe (Rear TWC) 
 43 
 440 
 32
 Front exhaust pipe (Rear TWC) x Center exhaust pipe 43 440 32
 Sub heated oxygen sensor (California only) x Front exhaust pipe 20 200 14
EG±174± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GE)

EMISSION CONTROL SYSTEMS (2JZ±GTE)
SYSTEM PURPOSE
The emission control systems are installed to reduce the amount of CO, HC and NOx exhausted from the
engine ((3), (4) and (5)), to prevent the atmospheric release of blow±by gas±containing HC (1) and evapo-
rated fuel containing HC being released from the fuel tank (2).
The function of each system is shown in the following table.
 System Abbreviation Function 
 
 
 
 
 
(1) Positive Crankcase Ventilation
(2) Evaporative Emission Control
(3) Exhaust Gas Recirculation
(4) Three±way Catalytic Converter
(5) Sequential Multiport Fuel Injection*
 
 
 
 
 
 
PCV
EVAP
EGR
TWC
SFI
 
 
 
 
 
 
Reduces HC
Reduces evaporated HC
Reduces NOx
Reduces CO, HC and NOx
Injects a precisely timed, optimum amount of fuel for reduced
exhaust emissions
Remark: * For inspection and repair of the SFI system, refer to the SFI section this manual.
PREPARATION
RECOMMENDED TOOLS
09082±00050 TOYOTA Electrical Tester Set


EQUIPMENT
 
 Tachometer 
 
 
 
Torque wrench 
 
 
 
Vacuum gauge 
 
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)EG±175

EMISSION CONTROL SYSTEMS (2JZ±GTE)
SYSTEM PURPOSE
The emission control systems are installed to reduce the amount of CO, HC and NOx exhausted from the
engine ((3), (4) and (5)), to prevent the atmospheric release of blow±by gas±containing HC (1) and evapo-
rated fuel containing HC being released from the fuel tank (2).
The function of each system is shown in the following table.
 System Abbreviation Function 
 
 
 
 
 
(1) Positive Crankcase Ventilation
(2) Evaporative Emission Control
(3) Exhaust Gas Recirculation
(4) Three±way Catalytic Converter
(5) Sequential Multiport Fuel Injection*
 
 
 
 
 
 
PCV
EVAP
EGR
TWC
SFI
 
 
 
 
 
 
Reduces HC
Reduces evaporated HC
Reduces NOx
Reduces CO, HC and NOx
Injects a precisely timed, optimum amount of fuel for reduced
exhaust emissions
Remark: * For inspection and repair of the SFI system, refer to the SFI section this manual.
PREPARATION
RECOMMENDED TOOLS
09082±00050 TOYOTA Electrical Tester Set
EQUIPMENT
 
 Tachometer 
 
 
 
Torque wrench 
 
 
 
Vacuum gauge 
 
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)EG±175

LAYOUT AND SCHEMATIC DRAWING
EG±176± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)

POSITIVE CRANKCASE VENTILATION
(PCV) SYSTEM
PCV VALVE INSPECTION
1. REMOVE PCV VALVE
(a) Disconnect the PCV hose from the PCV valve.
(b) Remove the PCV valve.
2. INSTALL CLEAN HOSE TO PCV VALVE
3. INSPECT PCV VALVE OPERATION
(a) Blow air into the cylinder head side, and check that air passes
through easily.
CAUTION: Do not suck air through the valve. Petroleum sub-
stances inside the valve are harmful.
(b) Blow air into the air intake chamber side, and check that air
passes through with difficulty.
If operation is not as specified, replace the PCV valve.
4. REMOVE CLEAN HOSE FROM PCV VALVE
5. REINSTALL PCV VALVE
PCV HOSES AND CONNECTORS
INSPECTION
VISUALLY INSPECT HOSES, CONNECTIONS AND GAS-
KETS
Check for cracks, leaks or damage.
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)EG±177

EVAPORATIVE EMISSION (EVAP)
CONTROL SYSTEM
FUEL VAPOR LINES, FUEL TANK AND
TANK CAP INSPECTION
1. VISUALLY INSPECT LINES AND CONNECTIONS
Look for loose connections, sharp bends or damage.
2. VISUALLY INSPECT FUEL TANK
Look for deformation, cracks or fuel leakage.
3. VISUALLY INSPECT FUEL TANK CAP
Check if the cap and/or gasket are deformed or damaged.
If necessary, repair or replace the cap.
CHARCOAL CANISTER INSPECTION
1. REMOVE CHARCOAL CANISTER
2. VISUALLY INSPECT CHARCOAL CANISTER
Look for cracks or damage.
3. CHECK FOR CLOGGED FILTER AND STUCK CHECK
VA LV E
(a) Using low pressure compressed air (4.71 kPa (0.048
kgf/cm
2, 0.68 psi)), blow into port C and check that air flows
without resistance from the other ports. EG±178
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)

(b) Blow air (4.71 kPa (0.048 kgf/cm2, 0.68 psi)) into port A, and
check that air does not flow from the other ports.
(c) Blow air (4.71 kPa (0.048 kgf/cm
2, 0.68 psi)) into port B, and
check that air does not flow from the other ports.
If operation is not as specified, replace the charcoal canister.
4. CLEAN FILTER IN CANISTER
Clean the filter by blowing 294 kPa (3 kgf/cm
2, 43 psi) of com-
pressed air into port C while holding port A and B closed.
NOTICE:

Do not attempt to wash the canister.

No activated carbon should come out.
5. REINSTALL CHARCOAL CANISTER
VSV INSPECTION
(See VSV for EVAP in SFI System)
CHECK VALVE INSPECTION
1. REMOVE CHECK VALVE
2. INSPECT CHECK VALVE
(a) Check that air flows from the blue port to the black port.
(b) Check that air does not flow from the black port to the blue
port.
If operation is not as specified, replace the check valve.
3. REINSTALL CHECK VALVE
HINT: Install the check valve with the black port facing the
purge port side of the throttle body.
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)EG±179

EXHAUST GAS RECIRCULATION (EGR)
SYSTEM
EGR SYSTEM INSPECTION
1. INSPECT AND CLEAN FILTER IN EGR VACUUM
MODULATOR
(a) Remove the cap and 2 filters.
(b) Check the filter for contamination or damage.
(c) Using compressed air, clean the filter.
(d) Reinstall the 2 filters and cap.
HINT: Install the filter with the coarser surface facing the at-
mospheric side (outward).
2. INSTALL VACUUM GAUGE
Using a 3±way connector, connect a vacuum gauge to the
hose between the EGR valve and vacuum modulator.
3. INSPECT SEATING OF EGR VALVE
Start the engine and check that the engine starts and runs at
at idle.
4. INSPECT VSV OPERATION WITH COLD ENGINE
(a) The coolant temperature should be below 50°C (122° F).
(b) From idle, race the engine to 3,500±4,000 rpm (throttle valve
opening angle to about 1/3 of maximum).
(c) Check that the EGR pipe is not hot.
(d) Check that the vacuum gauge indicates zero.
5. INSPECT VSV OPERATION WITH HOT ENGINE
(a) Warm up the engine to above 50°C (122°F)
(b) From idle, race the engine to 3,500±4,000 rpm (throttle valve
opening angle to about 1/3 of maximum).
(c) Check that the vacuum gauge indicates low vacuum.
6. REMOVE VACUUM GAUGE
Remove the vacuum gauge, and reconnect the vacuum
hoses to their proper locations.
7. INSPECT EGR VALVE
(a) Apply vacuum directly to the EGR valve with the engine
idling.
(b) Check that the engine runs rough or dies.
(c) Reconnect the vacuum hoses to the proper locations.
IF NO PROBLEM IS FOUND DURING THIS INSPECTION,
SYSTEM IS NORMAL; OTHERWISE INSPECT EACH
PART
VSV INSPECTION
(See VSV for EGR in SFI System) EG±180
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)

EGR VACUUM MODULATOR
INSPECTION
1. DISCONNECT VACUUM HOSES FROM EGR VACUUM
MODULATOR
Disconnect the 2 vacuum hoses from ports P and Q of the
EGR vacuum modulator.
2. INSPECT EGR VACUUM MODULATOR OPERATION
(a) Block port P with your finger.
(b) Blow air into port Q, and check that the air passes through to
the air filter side freely.
(c) Start the engine, and maintain speed at 3,500 rpm.
(d) Repeat the above test. Check that there is a strong
resistance to air flow.
3. RECONNECT VACUUM HOSES TO EGR VACUUM
MODULATOR
Reconnect the 2 vacuum hoses to the proper locations.
EGR VALVE INSPECTION
1. REMOVE EGR PIPE
(a) Loosen the union nut of the EGR pipe.
(b) Remove the 2 bolts, EGR pipe and gasket.
2. REMOVE EGR GAS TEMPERATURE SENSOR
3. REMOVE EGR VALVE
(a) Disconnect these hoses from the EGR valve:
(1) Vacuum hose
(2) Pressure hose
(b) Remove the 2 nuts, EGR valve and gasket.
± ENGINEEMISSION CONTROL SYSTEMS (2JZ±GTE)EG±181