engine LEXUS SC400 1991 Service Repair Manual
[x] Cancel search | Manufacturer: LEXUS, Model Year: 1991, Model line: SC400, Model: LEXUS SC400 1991Pages: 4087, PDF Size: 75.75 MB
Page 2414 of 4087

(e) Using SST, connect terminals +B and FP of the check(ºDIAGNOSISº) connector.
SST 09843±18020
(f) Reconnect the cable to the negative (±) terminal of the
battery.
(g) Turn the ignition switch ON.
NOTICE: Do not start the engine.
(h) Connect the test probes of the SST (wire) to the battery, and check that the fuel spray is as shown.
SST 09842±30055
NOTICE: Perform this check within the shortest possible
time.
3. INSPECT LEAKAGE (a) In the condition above, disconnect the test probes ofSST (wire) from the battery and check fuel leakage from
the injector.
SST 09842±30055
Fuel drop: One drop or less per minute
(b) Disconnect the cable from the negative (±) terminal of the battery.
(c) Remove SST.
SST 09268±41045, 09842±30050 and 09843±18020
FI±34
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName
Page 2418 of 4087

4. CONNECT CONNECTORSConnect the following connectors:w Cold start injector connector
w ISC valve connector
w (USA Spec.)
EGR valve connector
w (Exc. USA Spec.)
VSV connector for EGR system
w SV connector for fuel pressure control system
5. INSTALL THROTTLE BODY (a) Connect the following hoses:(1) PCV hose to throttle body
(2) Water by±pass hose to throttle body
(b) Install a new gasket and throttle body with the two bolts and two nuts.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
HINT: Use bolts 40 mm (1.57 in.) in length.
(c) Install the water by±pass pipe (from rear water bypass
joint) to the clamp on the engine wire cover.
(d) Connect the following hoses: (1) Water by±pass hose to the ISC valve
(2) (USA Spec.) Vacuum hose to throttle body
(3) (Exc. USA Spec.) Three vacuum hoses to throttle body
FI±38
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName
Page 2420 of 4087

8. INSTALL VSV FOR EVAP SYSTEMInstall the VSV with the two bolts.
9. INSTALL LH NO.3 TIMING BELT COVER (a) Install the three gaskets to the timing belt cover.
(b) Install the cord grommet to the high±tension cord.
(c) Install the cord grommet to the timing belt cover.
(d) Fit portion A of the timing belt cover, matching it with the
lower high±tension cord cover.
(e) Install the timing belt cover with the four bolts.
10. INSTALL RH ENGINE WIRE COVER (a) Fit portions A and B of the engine wire cover, matching
them with the lower high±tension cord cover and No.3
timing belt cover.
(d) Install the engine wire cover with the bolt.
11. INSTALL LH ENGINE WIRE COVER (a) Connect portions A and B engine wire cover to the wirebrackets.
(b) Set the VSV (for fuel pressure control system) wire in original position.
(c) Fit portions C and D of the engine wire cover, matching them with the lower high±tension cord cover and No.3
timing belt cover.
(d) Install the engine wire cover with the two bolts.
12. INSTALL UPPER HIGH±TENSION CORD COVER (a) Fit portion A of the upper high±tension cover, matching
it with the top of the lower high±tension cord cover.
FI±40
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName
Page 2421 of 4087

(b) Push the front side of the high±tension cord cover, andconnect the front side claw groove of the upper
high±tension cord cover to the claw of the lower
high±tension cord cover.
(c) Install the upper high±tension cord cover with the two bolts.
13. INSTALL INTAKE AIR CONNECTOR (a) Connect the end portions of the intake air connector tothe throttle body and air cleaner hose.
(b) Tighten the two hose clamps.
(c) Install the bolt holding the intake air connector to the
cylinder head cover.
(d) Connect the following hoses: (1) Air hose to ISC valve
(2) Air hose (from PS air control valve) to intake air con- nector
14. CONNECT CONTROL CABLES TO THROTTLE BODY Connect the following cables:(1) Accelerator cable
(2) A/T throttle control cable
(3) (w/ Cruise Control System) Cruise control actuator cable
15. INSTALL THROTTLE BODY COVER Install the throttle body cover and hose clamp with the two
bolts and cap nut.
16. C O N N E C T C A B L E TO N E G AT I V E T E R M I N A L O F BATTERY
17. FILL WITH ENGINE COOLANT (See page CO±7)
18. CHECK FOR FUEL LEAKS (See page FI±16) FI±41
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName
Page 2424 of 4087

(b) Remove the bolt holding the intake air connector to thecylinder head cover.
(c) Loosen the two hose clamps.
(d) Disconnect the intake air connector from the throttle
body and air cleaner hose, and remove the intake air
connector.
3. REMOVE UPPER HIGH±TENSION CORD COVER (a) Remove the two mounting bolts.
(b) Disconnect the front side claw groove of the cord cover
from the claw of the lower cover, and remove the cord
cover.
4. REMOVE RH ENGINE WIRE COVER Remove the bolt and wire cover.
5. DISCONNECT VACUUM SENSING HOSE FROM FUEL PRESSURE REGULATOR
FI±44
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName
Page 2426 of 4087

(e) Connect the fuel return pipe to the pressure regulatorwith new two gaskets and the union bolt.
Torque: 35 N Vm (360 kgf Vcm, 26 ft Vlbf)
(f) Tighten the lock nut.
Torque: 29 N Vm (300 kgf Vcm, 22 ft Vlb)
2. CONNECT VACUUM SENSING HOSE TO FUEL
PRESSURE REGULATOR
3. INSTALL RH ENGINE WIRE COVER (a) Fit portions A and B of the engine wire cover, matchingthem with the lower high±tension cord cover and No.3
timing belt cover.
(d) Install the engine wire cover with the bolt.
FI±46
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName
Page 2428 of 4087

Injectors
ON±VEHICLE INSPECTION
INSPECT INJECTOR RESISTANCE(a) Remove the engine wire covers and throttle body.(See steps 1 to 8 and 13 on pages FI±27 to 30)
(b) Disconnect the injector connectors.
(c) Using an ohmmeter, measure the resistance between the terminals.
Resistance: 13.4±14.2
If the resistance is not as specified, replace the injector.
(d) Reconnect the injector connectors.
(e) Reinstall the throttle body and engine wire covers.
(See steps 5 and 10 to 18 on pages FI±38 to 41)
FI±48
± Fuel System (Injectors)EFI SYSTEM
WhereEverybodyKnowsYourName
Page 2430 of 4087

REMOVAL OF INJECTORS
(See Components on page FI±49)
1. REMOVE AIR INTAKE CHAMBER (See steps 1 to 16 on pages FI±27 to 32)
2. DISCONNECT FUEL INLET HOSE FROM LH DELIVERY PIPE
Remove the pulsation damper and two gaskets, and discon-
nect the inlet hose.
3. DISCONNECT FUEL RETURN HOSE FROM FUEL RETURN PIPE
4. DISCONNECT EGR PIPE FROM RH CYLINDER HEAD Remove the bolt holding the EGR pipe to the cylinder head,
and disconnect the EGR pipe.
5. DISCONNECT ENGINE WIRE FROM INTAKE MANIFOLD Remove the two bolts, and disconnect the engine wire.
6. DISCONNECT ENGINE WIRE FROM DELIVERY PIPES AND REAR WATER BY±PASS JOINT
(a) Remove the four bolts holding the engine wire to thedelivery pipes, and disconnect the engine wire from the
delivery pipes.
(b) Remove the two bolts holding the engine wire to the rear
water by±pass joint, and disconnect the engine wire
from the rear water by±pass joint.
(c) Remove the two bolts holding the engine wire to the rear
side of the RH cylinder head, and disconnect the engine
wire from the RH cylinder head.
FI±50
EFI SYSTEM
± Fuel System (Injectors)
WhereEverybodyKnowsYourName
Page 2431 of 4087

(d) Disconnect the two engine wire connectors from theconnector bracket on the front side of the LH delivery
pipe.
(e) Disconnect the eight injector connector.
7. REMOVE FUEL RETURN PIPE (a) Remove the bolt holding the return pipe to the LHcylinder head.
(b) Remove the union bolt and two gaskets and return pipe.
8. REMOVE DELIVERY PIPES AND INJECTORS (a) Remove the four nuts holding the delivery pipe to theintake manifold.
(b) Remove the connector bracket, the two delivery pipes and eight injector assembly, four spacers and eight
insulators.
NOTICE: Be careful not to drop the injectors, when re-
moving the delivery pipe.
(c) Pull out the eight injectors from the delivery pipes.
(d) Remove the O±ring and grommet from each injector. FI±51
EFI SYSTEM
± Fuel System (Injectors)
WhereEverybodyKnowsYourName
Page 2433 of 4087

(g) Install the grommet and a new O±ring to the injector.
(h) Connect SST (hose) to the injector with SST (union),and hold the injector and union with SST (clamp).
SST 09268±41045
(i) Put the injector into the graduated cylinder.
HINT: Install a suitable vinyl hose onto the injector to prevent
gasoline from splashing out.
(j) Using SST, connect terminals +B and FP of the check (ºDIAGNOSISº) connector.
SST 09843±18020
(k) Reconnect the cable to negative (±) terminal of battery.
(l) Turn the ignition switch ON.
NOTICE: Do not start the engine.
(m) Connect SST (wire) to the injector and battery for 15 seconds, and measure the injection volume with a
graduated cylinder. Test each injector two or three
times.
SST 09842±30070
Volume: 55±70 cc (3.4±4.3 cu in.) per 15 sec.
Difference between each injector:
10 cc (0.6 cu in.) or less
If the injection volume is not as specified, replace the injector.
2. INSPECT LEAKAGE (a) In the condition above, disconnect the test probes ofSST (wire) from the battery and check the fuel leakage
from the injector.
SST 09842±30070
Fuel drop: One drop or less per minute
(b) Disconnect the battery negative (±) cable.
(c) Remove SST.
SST 09268±41045 and 09843±18020
(d) Reconnect the fuel inlet hose to the fuel tube.
SST 09631±22020
Torque: 30 N Vm (310 kgf Vcm, 22 ft Vlbf)
HINT: Use a torque wrench with a fulerum length of 30 cm
(11.81 in.). FI±53
EFI SYSTEM
± Fuel System (Injectors)
WhereEverybodyKnowsYourName