LEXUS SC400 1991 Service Repair Manual

COMPONENTS FOR REMOVAL AND INSTALLATION
FI±91EFI SYSTEM ± Electronic Control System (VSV for Fuel Pressure Control)
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INSPECTION OF VSV FOR FUEL
PRESSURE CONTROL
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE VSV (a) Disconnect the VSV connector.
(b) Disconnect the following hoses from VSV:(1) Vacuum hose (from fuel pressure regulator)
(2) Vacuum hose (from air intake chamber)
(c) (Exc. USA Spec.) Remove the bolt holding the water by±pass pipe to the
VSV.
(d) Remove the bolt and VSV.
FI±92
EFI SYSTEM
± Electronic Control System (VSV for Fuel Pressure Control)
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3. INSPECT VSV
A. Inspect VSV for open circuitUsing an ohmmeter, check that there is continuity between
the terminals.
Resistance (Cold): 37±44

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 ports E to G.
(b) Apply battery voltage across the terminals.
(c) Check that air flows from ports E to the filter.
If operation is not as specified, replace the VSV.
4. REINSTALL VSV (a) Install the VSV with the bolt.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
FI±93EFI SYSTEM ± Electronic Control System (VSV for Fuel Pressure Control)
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(b) (Exc. USA Spec.)Install the water by±pass pipe to the VSV with the bolt.
(c) Connect the following hoses to VSV: (1) Vacuum hose (from fuel pressure regulator)
(2) Vacuum hose (from air intake chamber)
(d) Connect the VSV connector.
5. RECONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
FI±94
EFI SYSTEM
± Electronic Control System (VSV for Fuel Pressure Control)
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VSV for EVAP
INSPECTION OF VSV FOR EVAP
(See Emission Control System on page EC±11) FI±95
± Electronic Control System (VSV f\
or EVAP)EFI SYSTEM
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VSV for EGR (Exc. USA Spec.)
INSPECTION OF VSV FOR EGR
(See Emission Control Systems on page EC±18)
FI±96
± Electronic Control Syst\
em (VSV for EGR (Exc. USA Spec.))EFI SYSTEM
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EGR Valve (USA Spec. only)
INSPECTION OF VSV FOR EGR
(See Emission Control Systems on page EC±21) FI±97
± Electronic Control System (E\
GR Valve (USA Spec. Only))EFI SYSTEM
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Water Temperature Sensor
COMPONENTS FOR REMOVAL AND
INSTALLATION
FI±98 ± Electronic Control Sys\
tem (Water Temperature Sensor)EFI SYSTEM
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INSPECTION OF WATER TEMPERATURE
SENSOR
1. REMOVE LOWER HIGH±TENSION CORD COVER(See steps 1, 2 and 5 to 12 on pages FI±27 to 29)
2. REMOVE RH IGNITION COIL (a) Disconnect the ignition coil connector.
(b) Remove the two bolts, and disconnect the ignition coil.
(c) Disconnect the cam position sensor connector from the
ignition coil bracket, and remove the ignition coil.
3. DISCONNECT HOSES Disconnect the following hoses:(1) Upper radiator hose from front water by±pass joint
(2) Lower radiator hose from water inlet
(3) Radiator reservoir hose from front water inlet hous-
ing
4. REMOVE WATER INLET AND INLET HOUSING (a) Disconnect the water by±pass hose from the water inlethousing.
(b) Remove the two bolts holding the water inlet housing to the water pump.
(c) Pull out the water inlet and inlet housing assembly.
(d) Remove the O±ring from the water inlet housing.
5. REMOVE WATER TEMPERATURE SENSOR (a) Disconnect the water temperature sensor connector.
(b) Remove the water temperature sensor and gasket. FI±99
EFI SYSTEM
± Electronic Control System (Water Temperature Sensor)
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6. INSPECT WATER TEMPERATURE SENSORUsing an ohmmeter, measure the resistance between the ter-
minals.
Resistance: Refer to the chart graph
If the resistance is not as specified, replace the sensor.
7. REINSTALL WATER TEMPERATURE SENSOR (a) Install a new gasket to the water temperature sensor.
(b) Install the water temperature sensor.
Torque: 20 N Vm (200 kgf Vcm, 14 ft Vlbf)
(c) Connect the water temperature sensor connector.
8. REINSTALL WATER INLET AND INLET HOUSING (a) Remove any old packing (FIPG) material and be carefulnot to drop any oil on the contact surfaces of the water
inlet housing and water pump.
w Using a razor blade and gasket scraper, remove all
the old packing (FIPG) material from the gasket
surfaces and sealing groove.
w Thoroughly clean all components to remove all the
loose material.
w Using a non±residue solvent, clean both sealing
surfaces.
(b) Apply seal packing to the sealing groove of the water
inlet housing as shown in the illustration.
Seal packing: Part No. 08826±00100 or equivalent
w Install a nozzle that has been cut to a 2±3 mm
(0.08±0.12 in.) opening.
HINT: Avoid applying an excessive amount to the surface.
w Parts must be assembled within 5 minutes of
application. Otherwise the material must be
removed and reapplied.
w Immediately remove nozzle from the tube and
reinstall cap.
(c) Install a new O±ring to the water inlet housing.
(d) Apply soapy water to the O±ring.
FI±100
EFI SYSTEM
± Electronic Control System (Water Temperature Sensor)
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