engine coolant LEXUS SC400 1991 Service Manual Online

ELECTRONIC CONTROL SYSTEM
The control system consists of sensors which detect various engine conditions, and a ECU which deter\
-
mines the injection volume (timing) based on the signals from the sens\
ors.
The various sensors detect the air intake volume, engine rpm, oxygen densit\
y in the exhaust gas, coolant
temperature, air intake temperature and atmospheric pressure etc. and convert the in\
formation into an electrical
signal which is sent to the ECU. Based on these signals, the ECU calculates th\
e optimum ignition timing for the
current conditions and operates the injectors.
The ECU not only controls the fuel injection timing, but also the self diag\
nostic function which records the
occurrence of a malfunction, ignition timing control, idle rpm control, \
EGR control, EVAP control, fuel pressure
control and fuel pump control. FI±9
EFI SYSTEM
± Operation
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REMOVAL OF COLD START INJECTOR
(See Components on page FI±26)
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 bodycover.
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 intake air
connector. FI±27
EFI SYSTEM
± Fuel System (Cold Start Injector)
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(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)
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REMOVAL OF INJECTORS
(See Components on page FI±27 )
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OF
BATTERY
CAUTION: Turn the ignition switch to ºLOCKº.
Disconnect the cable from the negative (±) terminal of the
battery. Wait at least 20 seconds before proceeding with
work.
2. DRAIN ENGINE COOLANT
3. REMOVE THROTTLE BODY WITH INTAKE AIR CONNECTOR
(See steps 2 to 6 on pages EM±10 and 11)
4. DISCONNECT NO.1 FUEL PIPE FROM DELIVERY PIPE Remove the union bolt and two gaskets, and disconnect the
fuel pipe.
HINT:
wPut a suitable container or shop towel under the delivery
pipe.
w Slowly loosen the union bolt.
5. DISCONNECT NO. 2 FUEL PIPE FROM FUEL PRESSURE
REGULATOR
Remove the union bolt and two gaskets, and disconnect the
fuel pipe from the pressure regulator.
HINT:
w Put a suitable container or shop towel under the
pressure regulator.
w Slowly loosen the union bolt.
6. REMOVE AIR INTAKE CHAMBER STAYS Remove the bolt, nut and intake chamber stay.
Remove the No. 1 and No. 2 stays.
FI±28
±
EFI SYSTEM Fuel System (Injectors)
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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
±
IGNITION SYSTEM Distributor
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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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PREPARATION
EG0AZ±0A
RECOMMENDED TOOLS
MA009±02
EQUIPMENT
\
 
\

\
Dial indicator with magnetic base 


\
 \
Micrometer
\
 
\

\
MirrorBrake hose
\
 
\

\

Steel square
\
 \
Thermometer
\
 
\

\
Torque wrench
\
 \
Vernier calipers
MA00B±02
COOLANT 
Item
 
Capacity
 
Classification 

Engine coolant (w/ Heater)10.8 liters (11.4 US qts, 9.5 lmp. qts)Ethylene±glycol base
MA00D±0E
LUBRICANT
 Item Capacity Classification 

Engine oil (Drain and refill)
w/ Oil filter change
/ Oil filt h
 

4.8 liters (5.1 US qts, 4.2 lmp. qts)
 

API grade SG or SH, Energy±Conserving II
or ILSAC multigrade, and recommended
 


g
w/o Oil filter change 


4.8 liters (5.1 US qts, 4.2 lm. qts)
4.5 liters (4.8 US qts, 4.0 lmp. qts) 


or ILSAC multigrade, and recommended
viscosity oil with SAE 5W±30 being pre-
ferred engine oil
 Brake fluid Ð SAE J1703 or FMVSS No.116 DOT3
 Automatic transmission fluid 1.9 liters (2.0 US qts, 1.7 lmp. qts) ATF TYPE T±II

Automatic transmission fluid
(Drain and refill)
1.9 liters (2.0 US qts, 1.7 lm . qts)

AT F TYPE TII
 




Differential oil 




1.35 liters (1.43 US qts, 1.19 lmp. qts) 




Hypoid gear oil API GL±5
Above±18
5C (0 5F): SAE 90
Below±18 5C (0 5F): SAE 80W±90 or 80W
±
MAINTENANCE (1UZ ± FE)MA±5
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6. REPLACE ENGINE OIL AND OIL FILTER(See Lubrication System on page EG±497)
Oil grade:
API grade SG or SH, Energy±Conserving II or ILSAC
multigrade engine oil. Recommended viscosity is as
shown in the illustration, with SAE 5W±30 being the
preferred engine oil.
Drain and refill capacity:
w/ Oil filter change
4.8 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)
7. REPLACE ENGINE COOLANT (See Cooling System on page EG±425)
Coolant capacity (w/ Heater):
10.8 liters (11.4 US qts, 9.5 lmp. qts)
HINT:
wUse a good brand of ethylene±glycol base coolant and
mix it according to the manufacturer's directions.
w Using coolant which includes more than 50 %
ethylene±glycol (but not more than 70 %) is
recommended.
NOTICE:
w Do not use a alcohol type coolant.
w The coolant should be mixed with demineralized water or
distilled water.
8. INSPECT CHARCOAL CANISTER
(a) Remove the charcoal canister.
(See Emission Control System on page EG±221)
(b) Visually inspect the canister case.
(c) Check for crogged each port and stuck check valve. wUsing low compressed air (4.71 kPa (48 gf/cm
2, 0.68
psi)), blow into port A and check that air flows without
resistance from the other ports.
w Blow low compressed air (4.71 kPa (48 gf/cm
2, 0.68
psi)) into port B and check that air does not flow from the
other ports.
If operation is not as specified, replace the charcoal canister.
±
MAINTENANCE (1UZ ± FE)MA±9
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19. BRAKE PEDAL
(a) Check that pedal for smooth operation.
(b) Check that the pedal has the proper reservedistance and freeplay.
(c) Check the brake booster function.
20. BRAKES At a safe place, check that the brakes do not
pull to one side when applied.
21. PARKING BRAKE
(a) Check that the pedal has the proper travel.
(b) On a safe incline, check that the vehicle is held securely with only the parking brake applied.
22. A U TO M AT I C T RANSMISSION PARK
MECHANISM
(a) Check the lock release button of the selector lever for proper and smooth operation.
(b) On a safe incline, check that the vehicle is held securely with the selector lever in the ªPº
position and all brakes released.
MA00T±0A
UNDER HOOD
23. WINDSHIELD WASHER FLUIDCheck that there is sufficient fluid in the tank.
24. ENGINE COOLANT LEVEL
Check that the coolant level is between the
LEVEL lines on the see±through reservoir at
normal temperature (20 5C (68 5F)).
25. RADIATOR AND HOSES
(a) Check that the front of the radiator is clean and not blocked with leaves, dirt or bugs.
(b) Check the hoses for cracks, kinks, rot or loose connections.
26. BATTERY ELECTROLYTE LEVEL
Check the indicator.
When the indicator color is blue, the condition
is satisfactory. A red color indicates that dis-
tilled water must be added, and white indicates
that charging is necessary. 27. BRAKE FLUID LEVEL
Check that the brake fluid level is near the up-
per level line on the see±through reservoir.
28. ENGINE DRIVE BELT Check drive belt for fraying, cracks, wear or oili-
ness.
29. ENGINE OIL LEVEL
Check that level on the dipstick with the engine
turned off.
30. POWER STEERING FLUID LEVEL Check the level on the dipstick.
The level should be in the ªHOTº or ªCOLDº
range depending on the fluid temperature.
31. AUTOMATIC TRANSMISSION FLUID LEVEL
(a) Park the vehicle on a level surface.
(b) With the engine idling and the parking and foot brake applied, shift the selector into all
positions from ªPº to ªLº, and then shift into ªPº.
(c) Turn and pull out the dipstick and wipe off the fluid with a clean rag.
Re±insert the dipstick fully and check that the
fluid level is in the ªHOTº range.
(d) Perform this check with the fluid at normal driving temperature (70 ± 80
C (158 ± 176
F)).
If the level is at the low side, add fluid.
NOTICE: Do not overfill.
HINT: Wait about 30 minutes before checking
the fluid level after extended driving at high
speeds in hot weather, driving in heavy traffic
or with a trailer.
32. EXHAUST SYSTEM Visually inspect for cracks, holes or loose sup-
ports.
If any change in the sound of the exhaust or
smell of the exhaust fumes is noticed, have the
cause located and corrected.
MA±20
±
MAINTENANCE (1UZ ± FE)
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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.
EM±8
±
ENGINE MECHANICAL Engine Tune±Up
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