LEXUS SC400 1991 Service Repair Manual

Ignition Main Relay
INSPECTION OF IGNITION MAIN RELAY
1. REMOVE IGNITION MAIN RELAY FROM RELAY BOX INENGINE COMPARTMENT
2. INSPECT IGNITION MAIN RELAY
A. Inspect relay continuity (a) Using an ohmmeter, check that there is continuity
between terminals 3 and 6.
(b) Check that there is continuity between terminals 4 and 5.
(c) Check that there is no continuity between terminals 1 and 2.
If continuity is not as specified, replace the relay.
B. Inspect relay operation (a) Apply battery voltage across terminals 3 and 6.
(b) Using an ohmmeter, check that there is continuitybetween terminals 1 and 2.
(c) Apply battery voltage across terminals 4 and 5.
(d) Check that there is continuity between terminals 1 and 2.
If operation is not as specified, replace the relay.
3. REINSTALL IGNITION MAIN RELAY
FI±86
± Electronic Control System (Igniti\
on Main Relay)EFI SYSTEM
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Cold Start Injector Time Switch
COMPONENTS FOR REMOVAL AND
INSTALLATION
FI±87 ± Electronic Control System (Cold St\
art Injector Time Switch)EFI SYSTEM
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INSPECTION OF COLD START
INJECTOR TIME SWITCH
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. REMOVE COLD START INJECTOR TIME SWITCH (a) Disconnect the injector time switch connector.
(b) Remove the injector time switch and gasket.
4. INSPECT COLD START INJECTOR TIME SWITCH Using an ohmmeter, measure the resistance between each
terminal.
Resistance:
STA±STJ 25±45
below 15 °C (59 °F)
65±85
above 30 °C (86 °F)
STA±Ground 25±85

If the resistance is not as specified, replace the switch.
5. REINSTALL COLD START INJECTOR TIME SWITCH (a) Install a new gasket to the injector time switch.
(b) Install the injector time switch.
Torque: 34 N Vm (350 kgf Vcm, 25 ft Vlbf)
(c) Connect the injector time switch connector.
6. REINSTALL RH IGNITION COIL (a) Install the ignition coil with the two bolts.
FI±88
EFI SYSTEM
± Electronic Control System (Cold Start Injector Time Switch)
WhereEverybodyKnowsYourName

(b) Install the cam position sensor connector to the ignitioncoil bracket.
(c) Connect the ignition coil connector.
7. REINSTALL LOWER HIGH±TENSION CORD COVER (See steps 1 to 13 and 16 to 18 on pages FI±39 to 41)FI±89
EFI SYSTEM
± Electronic Control System (Cold Start Injector Time Switch)
WhereEverybodyKnowsYourName

VSV for Fuel Pressure Control
FI±90 ± Electronic Control System (VSV for Fue\
l Pressure Control)EFI SYSTEM
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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)
WhereEverybodyKnowsYourName

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)
WhereEverybodyKnowsYourName

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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