1986 TOYOTA SUPRA check engine

IAC VALVE REMOVAL
1. REMOVE THROTTLE BODY
(See throttle body removal)
2. REMOVE IAC VALVE FROM THROTTLE BODY
Remove the 2 screws, IAC valve and O±ring.
IAC VALVE INSPECTION
INSPECT IAC VALVE OPERATION
(a) Apply battery voltage to terminals B1 and B2, and while
repeatedly grounding S1±S2±S3±S4±S 1 in sequence, and
check that the valve moves toward the closed position.
(b) Apply battery voltage to terminals B1 and B2, and while
repeatedly grounding S4±S3±S2±S1±S 4 in sequence,
check that the valve moves toward the open position.
If operation is not as specified, replace the IAC valve.
IAC VALVE INSTALLATION
1. INSTALL IAC VALVE TO THROTTLE BODY
(a) Install a new O±ring on the throttle body.
(b) Install the IAC valve with the 2 screws.
2. INSTALL THROTTLE BODY
(See throttle body installation)
± ENGINESFI SYSTEM (2JZ±GE)EG±227

ACOUSTIC CONTROL INDUCTION
SYSTEM (ACIS)
ON±VEHICLE INSPECTION
1. CONNECT VACUUM GAUGE
Using a 3±way connector, connect vacuum gauge to the vac-
uum hose between the actuator and VSV.
2. START ENGINE
3. INSPECT ACIS
(a) While the engine is idling, check that the vacuum gauge
needle does not move.
(b) Rapidly depress the accelerator pedal to fully open position
and check that the vacuum gauge needle momentarily
fluctuates approx. 33.3 kPa (250 mmHg, 9.84 in.Hg) or more.
(The actuator rod is pulled down.) If operation is not as
specified, check each part.
4. REMOVE VACUUM GAUGE
Remove the vacuum gauge, and reconnect the vacuum hose
to their proper locations. EG±228
± ENGINESFI SYSTEM (2JZ±GE)

(b) Disconnect the connector and hoses, and remove the
vacuum tank and VSV assembly:
(1) VSV connector
(2) Vacuum hose (from air intake chamber) from port B of
vacuum tank
(3) Vacuum hose (from actuator) from VSV
3. REMOVE VSV FROM VACUUM TANK
(a) Disconnect the vacuum hose from port A of the vacuum tank.
(b) Remove the screw and VSV.
VACUUM TANK INSPECTION
INSPECT VACUUM TANK
(a) Check that air flows from port A to B.
(b) Check that air does not flow from port B to A.
(c) Plug port B with your finger, and apply 53.3 kPa (400 mmHg,
15.75 in.Hg) of vacuum to port A, and check that there is no
change in vacuum after 1 minute.
If operation is not as specified, replace the vacuum tank.
VSV INSPECTION
(See VSV for ACIS) EG±230
± ENGINESFI SYSTEM (2JZ±GE)

(g) Remove the 5 bolts, nut, air intake chamber and 2 gaskets.
Torque: 27 NVm (270 kgfVcm, 20 ftVlbf)
INSTALLATION HINT: Install a new gasket to the air intake
chamber, facing the protrusion rearward.
INTAKE AIR CONTROL VALVE
INSPECTION
INSPECT INTAKE AIR CONTROL VALVE
(a) With 53.3 kPa (400 mmHg, 15.75 in.Hg) of vacuum applied
to the actuator, check that the actuator rod moves.
If operation is not as specified, turn the adjusting screw.
(b) 1 minute after applying the vacuum in (a), check that the
actuator rod does not return. EG±234
± ENGINESFI SYSTEM (2JZ±GE)

EFI MAIN RELAY
EFI MAIN RELAY INSPECTION
1. REMOVE EFI MAIN RELAY
LOCATION: In the engine compartment relay box.
2. INSPECT EFI MAIN RELAY
A. Inspect relay continuity
(a) Using an ohmmeter, check that there is continuity between
terminals 1 and 2.
(b) Check that there is no continuity between terminals 3 and 5.
If continuity is not as specified, replace the relay.
B. Inspect relay operation
(a) Apply battery voltage across terminals 1 and 2.
(b) Using an ohmmeter, check that there is continuity between
terminals 3 and 5.
If operation is not as specified, replace the relay.
3. REINSTALL EFI MAIN RELAY
± ENGINESFI SYSTEM (2JZ±GE)EG±235

VSV FOR ACIS
COMPONENTS FOR REMOVAL AND
INSTALLATION
VSV INSPECTION
1. REMOVE VSV
2. INSPECT VSV
A. Inspect VSV for open circuit
Using an ohmmeter, check that there is continuity between
the terminals.
Resistance:
At 205C (685F) 38.5±44.5

If there is no continuity, replace the VSV.
B. Inspect VSV for ground
Using an ohmmeter, check that there is no continuity be-
tween each terminal and the body.
If there is continuity, replace the VSV. EG±236
± ENGINESFI SYSTEM (2JZ±GE)

C. Inspect VSV operation
(a) Check that air flows from port E to the filter.
(b) Apply battery voltage across the terminals.
(c) Check that air flows from port E to F.
If operation is not as specified, replace the VSV.
3. REINSTALL VSV
VSV FOR FUEL PRESSURE CONTROL
(California only)
COMPONENTS FOR REMOVAL AND
INSTALLATION
± ENGINESFI SYSTEM (2JZ±GE)EG±237

VSV INSPECTION
1. REMOVE VSV
2. INSPECT VSV
A. Inspect VSV for open circuit
Using an ohmmeter, check that there is continuity between
the terminals.
Resistance:
At 205C (685F) 33±39

If there is no continuity, replace the VSV.
B. Inspect VSV for ground
Using an ohmmeter, check that there is no continuity be-
tween each terminal and the body.
If there is continuity, replace the VSV.
C. Inspect VSV operation
(a) Check that air flows from port E to G.
(b) Apply battery voltage across the terminals.
(c) Check that air flows from port E to the filter.
If operation is not as specified, replace the VSV.
3. REINSTALL VSV EG±238
± ENGINESFI SYSTEM (2JZ±GE)