LEXUS SC400 1991 Service Repair Manual

EG24R±02
CYLINDER HEADS REMOVAL
(See Components for Removal and Installation)
1. DISCONNECT TIMING BELT FROM CAMSHAFT TIMING PULLEYS
(See steps 1 to 29 on pages EG±46 to 54)
2. REMOVE CAMSHAFT TIMING PULLEYS Using SST, remove the bolt and timing pulley. Remove the 2
timing pulleys.
SST 09278±54012
3. REMOVE FAN BRACKET Remove the 2 bolts, 2 nuts and fan bracket.
NOTICE:
w Be careful not to drop anything inside the timing belt
cover.
w Do not allow the belt to come into correct with oil, water
or dust.
4. DISCONNECT POWER STEERING (PS) PUMP FROM
ENGINE
(a) Disconnect the vacuum hose from the air intake chamber.
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(b) Remove the nut and 3 bolts, and disconnect the PS pumpfrom the engine.
5. REMOVE TWC (FRONT)
(a) Remove the 4 bolts holding the pipe support bracket to the transmission.
(b) Remove the 4 bolts and nuts holding the front exhaust pipe to the TWC, and remove the pipe support bracket.
(c) Disconnect the front exhaust pipe from the TWC, and remove
the 2 gaskets.
(d) Using a 14 mm deep socket wrench, remove the 3 nuts, TWC
and gasket. Remove the 2 TWC.
6. REMOVE THROTTLE BODY COVER
(a) Disconnect the EVAP hose from the hose clamp.
(b) Remove the cap nut.
(c) Loosen the 2 bolts, and remove the hose clamp and throttle body cover.
7. DISCONNECT CONTROL CABLES FROM THROTTLE BODY
Disconnect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
8. REMOVE RH IGNITION COIL
(a) Disconnect the ignition coil connector.
(b) Remove the 2 bolts and ignition coil.
EG±76
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9. REMOVE WATER INLET AND INLET HOUSING
(a) Disconnect the water bypass hose from the IAC valve.
(b) Remove the 2 bolts holding the water inlet housing to waterpump.
(c) Pull out the water inlet and inlet housing assembly.
(d) Remove the O±ring from the water inlet housing.
10. REMOVE TIMING BELT REAR PLATES
Remove the 2 bolts and rear plate. Remove the 2 rear plates.
11. REMOVE VACUUM PIPE
(a) Disconnect the following hoses: (1) California:
Vacuum hose from throttle body
(2) Except California: 3 vacuum hoses from throttle body
(3) Vacuum hose from fuel pressure regulator
(4) 2 vacuum hoses from VSV for fuel pressure control
(5) Except California:
2 vacuum hoses from EGR vacuum modulator
(6) 2 vacuum hoses (from VSV for EVAP) from vacuum pipe
(7) Vacuum hose (from VSV for fuel pressure) from air in-
take chamber
(8) Vacuum hose (from charcoal canister) from vacuum pipe
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(b) Remove the 2 bolts, the vacuum pipe and hoses assembly.
12. California:REMOVE EGR VALVE
(a) Disconnect the EGR valve connector.
(b) Disconnect the following hoses:
(1) Water bypass hose from IAC valve
(2) Water bypass hose from water bypass pipe (from rearwater by5pass joint)
(c) Remove the 2 nuts, EGR valve and gasket.
13. Except California: REMOVE EGR VALVE AND VACUUM MODULATOR
(a) Disconnect the following hoses:
(1) Water bypass hose from IAC valve
(2) Water bypass hose from water bypass pipe (from rearwater bypass joint)
(3) 2 vacuum hoses from VSV for EGR
(b) Disconnect the hose clamp from the PCV hose.
EG±78
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(c) Remove the bolt, 2 nuts, the EGR valve, vacuum modulatorassembly and gasket.
14. REMOVE EGR VALVE ADAPTOR
(a) Disconnect the EGR gas temperature sensor connector.
(b) Disconnect the PCV hose from the cylinder head.
(c) Remove the 2 bolts, 2 nuts, EGR adaptor and gasket.
15. REMOVE IAC VALVE
(a) Disconnect the IAC valve connector.
(b) Disconnect the water bypass hose from the IAC valve.
(c) Remove the 2 nuts, IAC valve and gasket.
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16. REMOVE HEATER WATER VALVE FROM BODY
(a) Disconnect the VSV connector.
(b) Disconnect the bolt holding the engine wire clamp to thewater valve bracket.
(c) Remove the 2 bolts, and disconnect the water valve and bracket assembly.
17. REMOVE THROTTLE BODY
(a) Disconnect the following connectors: (1) Throttle position sensor connector
(2) w/ TRAC:
Sub±throttle position sensor connector
(3) w/ TRAC: Sub±throttle actuator connector
(b) Remove the 2 bolts and 2 nuts, and disconnect the throttle body from the air intake chamber.
(c) Disconnect the following hoses, and remove the throttle body:
(1) PCV hose from throttle body
(2) Water bypass hose from throttle body
(d) Remove the throttle body gasket.
18. REMOVE AIR INTAKE CHAMBER
(a) Disconnect the following hoses: (1) Brake booster vacuum hose from union on air intake
chamber
(2) Vacuum hose (from VSV for heater water valve) from air
intake chamber
EG±80
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(b) Remove the bolt, stud bolt and accelerator bracket.
(c) Remove the union bolt, union and 2 gaskets.
(d) Disconnect the following connectors:wCold start injector connector
w VSV connector for fuel pressure control
w Except California:
VSV connector for EGR
(e) Remove the union bolt and 2 gaskets, and disconnect the cold start injector tube from the RH delivery pipe.
CAUTION:
w Put a shop towel under the delivery pipe.
w Slowly loosen the union bolt.
(f) Remove the 2 bolts and gasket, and disconnect the EGR
pipe from the air intake chamber.
(g) Remove the 4 bolts, 8 nut and following parts: (1) VSV for fuel pressure
(2) Except California:VSV for EGR
(3) Transmission throttle cable bracket
(h) Disconnect the DLC1 from the air intake chamber.
(i) Remove the air intake chamber and 4 gaskets.
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(j) Remove the 3 bolts, the cold start injector, tube, lead wireassembly and gasket.
19. DISCONNECT HEATER WATER HOSES Disconnect the following hoses:
(1) Water hose from water bypass pipe
(2) Water hose from rear water bypass joint
20. DISCONNECT FUEL INLET HOSE FROM DELIVERY PIPE
Remove the pulsation damper and 2 gaskets, and discon-
nect the fuel inlet hose from the delivery pipe.
CAUTION:
w Put a shop towel under the delivery pipe.
w Slowly loosen the union bolts.
21. D I S C O N N E C T F U E L R E T U R N H O S E F R O M F U E L
RETURN PIPE
22. DISCONNECT EGR PIPE FROM RH CYLINDER HEAD Remove the bolt holding the EGR pipe to the RH cylinder
head, and disconnect the EGR pipe.
23. DISCONNECT ENGINE WIRE FROM INTAKE MANIFOLD Remove the 2 bolts, and disconnect the engine wire protector
from the intake manifold.
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24. DISCONNECT ENGINE WIRE FROM DELIVERY PIPES,REAR WATER BYPASS JOINT AND RH CYLINDER HEAD
(a) Remove the 4 bolts, and disconnect the engine wire protectors from the delivery pipes.
(b) Remove the 2 bolts, and disconnect the engine wire protector
from the water bypass joint.
(c) Remove the 2 bolts, and disconnect the engine wire protector
from the rear side of the RH cylinder head.
(d) Disconnect the 2 engine wire connectors from the connector bracket on the LH delivery pipe.
(e) Disconnect the 8 injector connectors.
25. REMOVE FUEL RETURN PIPE
(a) Remove the bolt holding the fuel return pipe to the rear side of the LH cylinder head.
(b) Remove the union bolt, 2 gaskets and fuel return pipe.
26. REMOVE DELIVERY PIPES AND INJECTORS
(a) Remove the 4 nuts holding the delivery pipes to intake manifold.
(b) Remove the connector bracket, the 2 delivery pipes and 8 injectors assembly.
NOTICE: Be careful not to drop the injectors when re-
moving the delivery pipes.
(c) Remove the 8 insulators and 4 spacers from the cylinder head.
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(d) Pull out the 8 injectors from the delivery pipes.
(e) Remove the O±ring and grommet from each injector.
27. REMOVE INTAKE MANIFOLDRemove the 6 bolts, 4 nuts, intake manifold and 2 gaskets.
28. REMOVE FRONT WATER BYPASS JOINT
(a) Disconnect the following connectors: (1) ECT sensor connector
(2) Cold start injector time switch connector
(3) ECT sender gauge connector
(b) Remove the bolt, and disconnect the engine wire protector from the water bypass joint.
(c) Remove the 4 nuts, water bypass joint and 2 gaskets.
29. REMOVE REAR WATER BYPASS JOINT
(a) Remove the bolt holding the water bypass pipe to the LH rear
engine hanger.
(b) Remove the 4 nuts, water bypass joint and 2 gasket.
EG±84
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