1991 LEXUS SC400 check engine

9. INSTALL CATALYTIC CONVERTERS (MAIN)Install a new gasket and the catalytic converter with three
new nuts. Install the two catalytic converters.
Torque: 62 N Vm (630 kgf Vcm, 46 ft Vlbf)
10. INSTALL FRONT EXHAUST PIPE
(a) Temporarily install the pipe support stay with the fourbolts.
(b) Install three new gaskets, the exhaust pipe and pipe support stay with the six bolts and nuts.
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
(c) Tighten the four bolts holding the pipe support bracket
to the transmission.
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
(d) Install the two sub±oxygen sensors to the exhaust pipe.
Torque: 44 N Vm (450 kgf Vcm, 33 ft Vlbf)
HINT:
w Before installing the s ub±oxygen sensor, twist the
sensor wire counterclockwise 3 1/2 turns.
w After installing the sub±oxygen sensor, check that the
sensor wire is not twisted. If it is twisted, remove the
sub±oxygen sensor and reinstall it.
(e) Install the wire grommets to the floor.
11. CONNECT ENGINE WIRE TO CABIN (a) Push in the engine wire through the cowl panel.
(b) Install the engine wire clamp with the three bolts.
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31. INSTALL THROTTLE BODY COVERInstall the throttle body cover and hose clamp with the two
bolts and cap nut.
32. INSTALL DRIVE BELT Install the drive belt by turning the drive belt tensioner coun-
terclockwise.
HINT: The pulley bolt for the belt tensioner has a left±hand
thread.
33. INSTALL BATTERY
34. FILL WITH ENGINE COOLANT (See page CO±7)
35. FILL COOLING FAN RESERVOIR TANK WITH FLUID (See page CO±23)
36. FILL WITH ENGINE OIL (See page LU±7)
Capacity:
Drain and refill
w/Oil filter change4.8 liters (5.1 US qts, 4.2 lmp. qts)
w/o Oil filter change 4.5 liters (4.8 US qts, 4.0 lmp. qts)
Dry fill 6.0 liters (6.3 US qts, 5.3 lmp. qts)
37. START ENGINE AND CHECK FOR LEAKS
38. CHECK AUTOMATIC TRANSMISSION FLUID LEVEL
39. CHECK IGNITION TIMING (See page IG±28)
Ignition timing:
8±125 BTDC @ idle
(w/ Terminals TE1 and E1 connected)
40. INSTALL ENGINE UNDER COVER
41. INSTALL HOOD
42. PERFORM ROAD TEST Check for abnormal noise, shock, slippage, correct shift
points and smooth operation.
32. RECHECK ENGINE COOLANT AND ENGINE OIL LEVELS
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ENGINE TUNE±UP
INSPECTION OF ENGINE COOLANT
1. INSPECT ENGINE COOLANT LEVEL AT RESERVOIRTANK
The engine coolant level should be between the LOW and
FULL lines.
If low, check for leaks and add engine coolant up to the FULL
line.
2. INSPECT ENGINE COOLANT QUALITY There should not be any excessive deposits of rust or scales
around the radiator cap or reservoir tank filler hole, and the
engine coolant should be free from oil.
If excessively dirty, clean the engine coolant passages and
flush the cooling system.
INSPECTION OF ENGINE OIL
1. INSPECT ENGINE OIL QUALITYCheck the oil for deterioration, presence of water, discoloring
or thinning.
If the quality is poor, replace the oil.
Oil grade: API grade SG, Energy±Conserving II multi- grade. Recommended viscosity is as shown,
with SAE 5W±30 being the preferred engine
oil.
Drain and refill oil capacity:
w/ Oil filter change
4.8 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 LEVELThe 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:
1.250±1.270 when fully charged at 20 5C (68 5F)
If not within specification, charge the battery.
(b) Check the electrolyte level of each cell.
If insufficient, refill with distilled (or purified) water.
2. CHECK BATTERY TERMINALS Check the battery terminals for looseness or corrosion.
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 outside of the air
filter.
3. REINSTALL AIR FILTER
EM±8
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INSPECTION OF HIGH±TENSION CORDS
INSPECT HIGH±TENSION CORD
RESISTANCE
(See page IG±7)
Maximum resistance: 25 K
per cord
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: Cracks on rib side of a drive belt are considered accept-
able. If the drive belt has chunks missing from the ribs, it
should be replaced.
(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 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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9. REMOVE NO. 3, NO. 1 AND NO. 2 CYLINDER HEADCOVERS
(a) Remove the 12 bolts and four nuts.
(b) Remove the cylinder head covers and gaskets.
10. SET NO. 1 CYLINDER TO TDC/COMPRESSION (a) Turn the crankshaft pulley and align its groove withtiming mark º0º of the No. 1 timing belt cover.
NOTICE: Always turn the crankshaft clockwise.
(b) Check that the timing marks of the camshaft timing pulleys are aligned with the timing marks of the No. 4
timing belt cover.
If not, turn the crankshaft one revolution (360 5).
11. INSPECT VALVE CLEARANCE (a) Uniformly tighten the bearing cap bolts in severalpasses.
Torque: 20 N Vm (200 kgf Vcm, 14 ft Vlbf)
(b) Check only those valves indicated in the illustration.
w Using a feeler gauge, measure the clearance
between the valve lifter and camshaft.
w Record the valve clearance measurements of
those that are out of specification. They will be used
later to determine the required replacement
adjusting shim.
Valve clearance (Cold):
Intake 0.15±0.25 mm (0.006±0.010 in.)
Exhaust 0.25±0.35 mm (0.010±0.014 in.)
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(c) Turn the crankshaft 2/3 of a revolution (240
), check
only the valves indicated in the illustration.
Measure the valve clearance.
[See procedure in step (b)]
(d) Turn the crankshaft a further 2/3 of a revolution (240
),
check only the valves indicated in the illustration.
Measure the valve clearance.
[See procedure in step (b)]
12. ADJUST VALVE CLEARANCE (a) Remove the adjusting shim.w Turn the camshaft so that the cam lobe for the valve
to be adjusted faces up.
w Turn the valve lifter with a screwdriver so that the
notches would be per pendicular to the camshaft.
w Using SST (A), press down the valve lifter and
place SST (B) between the camshaft and valve
lifter. Remove SST (A).
SST 09248±55020 (09248±05011 (A), 09248±05021 (B))
HINT:
w Choose either method A or B in using SST on either side
of the cam lobe.
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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.
EM±14
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