LEXUS SC400 1991 Service Repair Manual

wPosition SST on the edge of the lifter for easy removal
of the shim.
w Remove the adjusting shim with a small screwdriver and
a magnetic finger.
(b) D e t e r m i n e t h e r e p l a c e m e n t a d j u s t i n g s h i m s i z e according to the following formula or Charts:
w Using a micrometer, measure the thickness of the
removed shim.
w Calculate the thickness of a new shim so the valve
clearance comes within specified value.
T Thickness of used shim
A Measured valve clearance
N Thickness of new shim
Intake N = T + (A±0.20 mm)
Exhaust N = T + (A±0.30 mm)
w Select a new shim with a thickness as close as
possible to the calculated values.
HINT: Shims are available in seventeen sizes in increments
of 0.05 mm, from 2.50 mm to 3.30 mm.
(c) Install a new adjusting shim. w Place a new adjusting shim on the valve lifter, with
imprinted numbers facing down.
w Press down the valve lifter with SST (A), and
remove SST (B).
SST 09248±55020
(d) Recheck the valve clearance.
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13. REINSTALL NO. 3, NO. 1 AND NO. 2 CYLINDER HEADCOVERS
(a) Remove any oil packing (FIPG) material.
(b) Apply seal packing to the cylinder head as shown in theillustration.
Seal packing: Part No. 08826±00080 or equivalent
(c) Install the gaskets to the No. 1 and No. 2 cylinder headcovers.
(d) Install the cylinder head cover with the 12 bolts and four
nuts.
Torque: 5.4 N Vm (55 kgf Vcm, 48 in. Vlbf)
14. R E C O N N E C T H I G H ± T E N S I O N C O R D S TO S PA R K
PLUGS
(a) Connect the high±tension cord to the spark plug.
HINT: The No. 4 high±tension cord must be raised 10 5 from
the perpendicular line.
(b) Connect the two high±tension cord clamps to the No. 3 cylinder head cover.
(c) Install the high±tension cord clamp with the bolt.
15. REINSTALL CYLINDER HEAD REAR COVER AND NO. 3 TIMING BELT COVER
(a) Using a 5 mm hexagon wrench, install the cylinder head
rear cover and No. 3 timing belt cover with the ten bolts.
(b) Install the oil filler cap.
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16. REINSTALL THROTTLE BODY WITH INTAKE AIRCONNECTOR
(a) Place a new gasket so the protrusion face the intakechamber, and set the throttle body with intake air
connector.
(b) Connect the two water by±pass hoses to the throttle body.
(c) Install the VSV nut.
(d) Install the air intake connector with the four bolts and two
nuts.
Torque: 21 N Vm (210 kgf Vcm, 15 ft Vlbf)
(e) Connect the following hoses and connectors:
(1) PCV hose
(2) Three vacuum hoses
(3) VSV (for EGR) connector
(4) Throttle position sensor connector
(5) IAC valve connector
(6) (w/ TRAC) Sub±throttle position sensor connector
(7) (w/ TRAC) Sub±throttle actuator connector
(8) (USA spec. only) EGR gas temperature sensor connector
17. REINSTALL THROTTLE BODY BRACKET Install the throttle body bracket with the four nuts.
Torque: 21 N Vm (210 kgf Vcm, 15 ft Vlbf)
18. REINSTALL EGR PIPE
(a) Install a new gasket and the EGR pipe with the two bolts.
Torque: 21 N Vm (210 kgf Vcm, 15 ft Vlbf)
(b) Tighten the union nut.
Torque: 64 N Vm (650 kgf Vcm, 47 ft Vlbf)
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19. REINSTALL AIR CLEANER HOSE(a) Install the air cleaner hose with two hose clamps.
(b) Connect the following hoses:(1) PS air hose to No. 4 timing belt cover
(2) PCV hose to No. 2 cylinder head cover
20. RECONNECT CONTROL CABLES TO THROTTLE BODY
Connect the following hoses:
(1) Accelerator cable
(2) (A/T) Throttle control cable
(3) Cruise control actuator cable
21. RE CO NNE CT CABLE TO NE G ATIV E TE RMINAL OF BATTERY
INSPECTION OF IGNITION TIMING
(See page IG±14)
Ignition timing:
105 BTDC @ idle
(w/ Terminals TE1 and E1 connected)
INSPECTION OF IDLE SPEED
HINT: Initial conditions (See step 1 on page EM±20)
Idle speed: M/T 700
+ 50 rpm
A/T 650
+ 50 rpm (N range)
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ENGINE TUNE±UP
INSPECTION OF ENGINE COOLANT
1. INSPECT ENGINE COOLANT LEVEL AT RESERVOIRTANK
The coolant level should be above the ºCOLD LEVELº at
normal temperature (20 5C (68 5F)).
If low, check for leaks and add coolant up to the ºCOLD
LEVELº.
2. INSPECT ENGINE COOLANT QUALITY There should be any excessive deposits of rust or scales
around the radiator cap or reservoir tank filler hole, and the
coolant should be free from oil.
If excessively dirty, clean the coolant passages and replace
the coolant.
INSPECTION OF ENGINE OIL
1. INSPECT ENGINE OIL QUALITYCheck the oil for deterioration, entry of water, discoloring or
thinning.
If the quality is poor, replace the oil.
Oil grade: API grade SG, Energy±Conserving II multigrade.
Recommended viscosity is as shown, with SAE
5W±30 being the preferred engine oil.
Drain and refill oil capacity: w/ oil filter change4.8 liter (5.1 US qts, 4.2 lmp. qts)
w/o oil filter change 4.5 liter (4.8 US qts, 4.0 lmp. qts)
2. INSPECT ENGINE OIL LEVEL The oil level should be between the ºLº and ºFº marks on the
dipstick.
If low, check for leakage and add oil up to ºFº mark.
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INSPECTION OF BATTERY
1. INSPECT BATTERY SPECIFIC GRAVITY ANDELECTROLYTE LEVEL
(a) Check the specific gravity of each cell.
Standard specific gravity:
1.27±1.29 when fully charged at 20 5C(68 5F)
If not within specification, charge the battery.
(b) Check the electrolyte quantity of each cell.
If insufficient, refill with distilled (or purified) water.
2. CHECK BATTERY TERMINALS Check that the battery terminals are not loose or corroded.
INSPECTION AND CLEANING OF AIR
FILTER
1. REMOVE AIR FILTER(a) Open the air cleaner cap.
(b) Remove the air filter.
2. INSPECT AIR FILTER (a) Visually check that the air filter is not excessivelydamaged or oily.
(b) Clean the air filter with compressed air.
First blow from the inside thoroughly, then blow off the out-
side of the air filter.
3. REINSTALL AIR FILTER
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INSPECTION OF HIGH±TENSION CORDS
1. REMOVE HIGH±TENSION CORDS (See page IG±11)
2. INSPECT HIGH±TENSION CORDS (b) Using an ohmmeter, measure the resistance.
Maximum resistance: 25 k
per cord
If the resistance is greater than maximum, replace the cord.
3. REINSTALL HIGH±TENSION CORDS (See page IG±16)
INSPECTION OF DRIVE BELT
INSPECT DRIVE BELT
HINT: A belt tensioner is used, so checking the belt tension
is not necessary.
(a) Visually check the drive belt for excessive wear, frayedcords etc.
If necessary, replace the drive belt.
HINT:
w Cracks on rib side of a drive belt are considered
acceptable. If the drive belt has chunks missing from the
ribs, it should be replaced.
w The drive belt tension can be released by turning the
belt tensioner counterclockwise. The pulley bolt for the
belt tensioner has a left±hand thread.
(b) Check the belt tensioner operation. w Check that the belt tensioner moves downward
when the drive belt is pressed down at the points
indicated in the illustration with approx. 98 N (10
kgf, 22.0 lbf) of force.
w Check the alignment of the belt tensioner pulley to
make sure the drive belt has not slipped off the
pulley.
If necessary, replace the belt tensioner. w Check that the arrow mark on the belt tensioner
falls within area A of the scale.
If it is outside area A, replace the drive belt.
HINT:
w When a new belt is installed, it should lie within area B.
If not, the drive belt is not correct.
w After installing a belt, check that it fits properly in the
ribbed grooves.
w Check by hand to confirm that the belt has not slipped
out of the groove on the bottom of the pulley.
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INSPECTION AND ADJUSTMENT OF
VALVE CLEARANCE
HINT: Inspect and adjust the valve clearance when the
engine is cold.
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. DRAIN ENGINE COOLANT (See page CO±6)
3. REMOVE THROTTLE BODY COVER (a) Remove the mounting cap nut.
(b) Loosen the two bolts, and remove the throttle body
cover.
4. DISCONNECT CONTROL CABLES FROM THROTTLE BODY
Disconnect the following cables:(1) Accelerator cable
(2) A/T throttle control cable
(3) (w/ Cruise Control System) Cruise control actuator cable
5. REMOVE INTAKE AIR CONNECTOR (a) Disconnect the following hoses:(1) Air hose from ISC valve
(2) Air hose (from PS air control valve) from intake
air connector
(b) Remove the bolt holding the intake air connector to the cylinder 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 throttle body.
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