LEXUS SC400 1991 Service Repair Manual
Manufacturer: LEXUS, Model Year: 1991, Model line: SC400, Model: LEXUS SC400 1991Pages: 4087, PDF Size: 75.75 MB
Page 2541 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.
11. 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
12. CONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
13. CHECK THAT ENGINE STARTS
±
IGNITION SYSTEM High±Tension Cords and Cord ClampsIG±19
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IGNITION COILS
COMPONENTS FOR REMOVAL AND
INSTALLATION
IG±20±
IGNITION SYSTEM Ignition Coils
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REMOVAL OF RH IGNITION COIL
(See Components on page IG±20)
1. REMOVE RH ENGINE WIRE COVER (See steps 1, 3 and 4 on pages IG±11 and 12)
2. DISCONNECT HIGH±TENSION CORD (See step 9 on pages IG±13 and 14)
3. DISCONNECT IGNITION COIL CONNECTOR
4. REMOVE IGNITION COIL (a) Remove the three bolts, and disconnect the ignition coil.
(b) Disconnect the cam position sensor connector, and
remove the ignition coil.
REMOVAL OF LH IGNITION COIL
(See Components on page IG±20)
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
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. DISCONNECT IGNITION COIL CONNECTOR
3. DISCONNECT HIGH±TENSION CORD (See step 9 on pages IG±13 and 14)
4. DISCONNECT NOISE FILTER FROM IGNITION COIL Remove the bolt, and disconnect the noise filter.
5. REMOVE IGNITION COIL Remove the two bolts and ignition coil.
±
IGNITION SYSTEM Ignition CoilsIG±21
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Page 2544 of 4087

INSTALLATION OF RH IGNITION COIL
(See Components on page IG±20)
1. INSTALL IGNITION COIL (a) Install the ignition coil with the three bolts.
(b) Install the cam position sensor connector to the ignition
coil bracket.
2. CONNECT IGNITION COIL CONNECTOR
3. CONNECT HIGH±TENSION CORD
(See step 4 on pages IG±16 and 17)
4. INSTALL RH ENGINE WIRE COVER (See steps 8, 10, 12 and 13 on pages IG±11 and 12)
INSTALLATION OF LH IGNITION COIL
(See Components on page IG±20)
1. INSTALL IGNITION COIL Install the ignition coil with the two bolts.
2. INSTALL NOISE FILTER TO IGNITION COIL Install the noise filter with the bolt.
3. CONNECT HIGH±TENSION CORD
(See step 4 on pages IG±16 and 17)
4. CONNECT IGNITION COIL CONNECTOR
5. CONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
IG±22
±
IGNITION SYSTEM Ignition Coils
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Page 2545 of 4087

DISTRIBUTOR
COMPONENTS FOR REMOVAL AND
INSTALLATION
±
IGNITION SYSTEM DistributorIG±23
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Page 2546 of 4087

REMOVAL OF DISTRIBUTOR
(See Components on page IG±23)
1. DRAIN ENGINE COOLANT (See page CO±6)
2. DISCONNECT RADIATOR HOSE FROM WATER INLET
3. REMOVE NO.3 TIMING BELT COVERS
(See steps 1 to 8 on pages IG±11 to 13)
4. REMOVE DRIVE BELT IDLER PULLEY Remove the pulley bolt, cover plate and idler pulley.
5. REMOVE RH NO.2 TIMING BELT COVER (a) Disconnect the cam position sensor connector from theignition coil bracket.
(b) Disconnect the cam position sensor wire from the clamp
on the timing belt cover.
(c) Remove the five mounting bolts.
(d) Disconnect the connector grommet from the timing belt cover.
(e) Disconnect the wire clamp from the timing belt cover, and remove the timing belt cover and four gaskets.
6. REMOVE LH NO.2 TIMING BELT COVER (a) Disconnect the cam position sensor wire from the clamp
on the timing belt cover.
(b) Disconnect the cam position sensor connector.
(c) Remove the three mounting bolts.
(d) Disconnect the connector grommet from the timing belt cover, and remove the timing belt cover and two
gaskets.
IG±24
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IGNITION SYSTEM Distributor
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Page 2547 of 4087

7. DISCONNECT HIGH±TENSION CORDS FROMDISTRIBUTOR CAPS
Disconnect the high±tension cords at the rubber boot. Do not
pull on the cord.
NOTICE: Pulling or bending the cords may damage the
conductor inside.
8. REMOVE DISTRIBUTOR CAPS Loosen the three bolts, and remove the distributor cap. Re-
move the two distributor caps.
HINT: Arrange the distributor caps (RH side and LH side).
9. REMOVE DISTRIBUTOR ROTORS Loosen the two bolts, and remove the distributor rotor. Re-
move the two distributor rotors.
HINT: Arrange the distributor rotors (RH side and LH side).
10. REMOVE DISTRIBUTOR HOUSINGS (a) (RH Distributor Housing)Disconnect the cam position sensor connector.
(b) Re mo ve th e th re e bo lts an d distrib u to r ho u sin g . Remove the two distributor housings.
11. REMOVE CAM POSITION SENSORS FROM DISTRIBUTOR HOUSINGS
Remove the bolt, screw and cam position sensor.
Remove the two cam position sensors.
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IGNITION SYSTEM DistributorIG±25
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INSTALLATION OF DISTRIBUTOR
(See Components on page IG±23)
1. INSTALL CAM POSITION SENSORS TO DISTRIBUTOR HOUSINGS
Install the cam position sensor with the bolt and screw. Install
the two cam position sensors.
Torque: 6.4 N Vm (65 kgf Vcm, 56 in. Vlbf)
HINT:
w The RH distributor housing is marked with ºRº.
w The LH distributor housing is marked with ºLº.
2. INSTALL RH DISTRIBUTOR HOUSING (a) Install the distributor housing with the three bolts.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
HINT:
w The RH distributor housing is marked with ºRº.
w Each bolt length is indicated in the illustration.
Bolt length: A 38 mm (1.50 in.)
B 96 mm (3.78 in.)
(b) Connect the cam position sensor connector.
3. INSTALL LH DISTRIBUTOR HOUSING (a) Install the distributor housing with the three bolts.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
HINT:
w The LH distributor housing is marked with ºLº.
w Each bolt length is indicated in the illustration.
Bolt length: A 38 mm (1.50 in.)
B 80 mm (3.15 in.)
4. INSTALL DISTRIBUTOR ROTORS (a) Align the protrusion of the distributor rotor with thegroove of the camshaft timing pulley.
(b) Install the distributor rotor with the two bolts. Install the two distributor rotors.
Torque: 3.8 N Vm (39 kgf Vcm, 34 in. Vlbf)
IG±26±
IGNITION SYSTEM Distributor
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5. INSTALL DISTRIBUTOR CAPSInstall the distributor cap with the three bolts. Install the two
distributor caps.
Torque: 3.8 N Vm (39 kgf Vcm, 34 in. Vlbf)
6. CONNECT HIGH±TENSION CORDS TO DISTRIBUTOR
CAPS
Connect the ten high±tension cords.
NOTICE: Connect the high±tension cord by pressing on
the correct place as shown in the illustration.
If not done this way, the high±tension cord will interfere with
the camshaft timing pulley.
7. INSTALL RH NO.2 TIMING BELT COVER (a) Install the four gaskets to the timing belt cover.
(b) Install the connector grommet to the timing belt cover.
(c) Install the timing belt cover with the five bolts.
Torque: 16 N Vm (160 kgf Vcm, 12 ft Vlbf)
HINT (12 mm head bolt): Use bolts 106 mm (4.17 in.) in
length.
(d) Install the wire clamp to the timing belt cover.
(e) Install the cam position sensor wire to the wire clamp on
the timing belt cover.
(f) Install the cam position sensor connector to the ignition coil bracket.
8. INSTALL LH NO.2 TIMING BELT COVER (a) Install the two gaskets to the timing belt cover.
(b) Run the cam po sition sensor wire through the timing belt
cover hole.
(c) Install the timing belt cover and connector bracket with the three bolts.
(d) Connect the cam position sensor connector.
(e) In sta ll th e ca m po sitio n se n so r c onnector to the
connector bracket.
(f) Install the cam position sensor wire to the wire clamp on
the timing belt cover.
(g) Install the connector grommet to the timing belt cover.
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IGNITION SYSTEM DistributorIG±27
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Page 2550 of 4087

9. INSTALL DRIVE BELT IDLER PULLEYInstall the idler pulley and cover plate with the pulley bolt.
Torque: 37 N Vm (380 kgf Vcm, 27 ft Vlbf)
10. INSTALL NO.3 TIMING BELT COVERS
(See steps 5 to 9 and 11 on pages IG±17 to 19)
11. CONNECT RADIATOR HOSE TO WATER INLET
12. 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
13. FILL ENGINE WITH COOLANT (See page CO±6)
14. WARM UP ENGINE Allow the engine to warm up to normal operating tempera-
ture.
15. CONNECT TACHOMETER Connect the tester probe of a tachometer to terminal IG of
the check (ºDIAGNOSISº) connector.
HINT: Set the tachometer to the 4±cylinder range.
NOTICE:
w Never allow the tachometer tester probe to touch ground
as it could result in damage to the igniter and/or ignition
coil.
w As some tachometers are not compatible with this
ignition system, we recommend that you confirm the
compatibility of your unit before use.
16. CHECK IGNITION TIMING
(a) Using SST, connect terminals TE1 and E1 of the check(ºDIAGNOSISº) connector.
SST 09843±18020
(b) C onnect the tester probe of a timing light to the
high±tension cord for No.6 cylinder.
IG±28
±
IGNITION SYSTEM Distributor
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