efi LEXUS SC400 1991 Service User Guide

ON±VEHICLE INSPECTION
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 gravity is less than specification, charge the battery.
(b) Check the electrolyte quantity of each cell.
If insufficient, refill with distilled (or purified) water.
HINT: Check the indicator as shown in the illustration.
2. CHECK BATTERY TERMINALS, FUSIBLE LINKS AND FUSES
(a) Check that the battery terminals are not loose orcorroded.
(b) Check the fusible links and fuses for continuity.
H±fuse: ALT 150A AM1 100A
AM2 30A
M±fuse: IG SW 40A
Fuse: IGN 7.5A ENGINE 7.5A
INJ 30A
3. INSPECT DRIVE BELTHINT: 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.
±
CHARGING SYSTEM On±Vehicle InspectionCH±5
WhereEverybodyKnowsYourName

CodeMaterial
name Heat*
resistant
temperature
limit
°C (°F) Resistance to
alcohol or gasoline Notes
PMMA Polymethyl
Methacrylate 80
(176) Alcohol is harmless if applied only
for short time in small amounts.
Avoid dipping or immers-
ing in alcohol, gasoline,
solvents, etc.
POM Polyoxymethylene
(Polyacetal) 100
(212) Alcohol and gasoline are
harmless.
Most solvents are
harmless.
PP Polypropylene 80
(176) Alcohol and gasoline are
harmless.
Most solvents are
harmless.
PPO Modified
Polyphenylene
Oxide
100
(212) Alcohol is harmless. Gasoline is harmless if
applied only for quick
wiping to remove
grease.
PS Polystyrene 60
(140) Alcohol and gasoline are harm-
less if applied only for short time
in small amounts. Avoid dipping or immers-
ing in alcohol, gasoline,
solvents, etc.
PUR Polyurethane 80
(176) Alcohol is harmless if applied only for
very short time in small amounts (e.g.,
quick wiping to remove grease).
Avoid dipping or immers-
ing in alcohol, gasoline,
solvents, etc.
PVC Polyvinylchloride
(Vinyl) 80
(176) Alcohol and gasoline are harmless if
applied only for short time in small
amounts (e.g., quick wiping to remove
grease). Avoid dipping or immers-
ing in alcohol, gasoline,
solvents, etc.
SAN Styrene
Acrylonitrile 80
(176) Alcohol is harmless if applied only
for short time in small amounts
(e.g., quick wiping to remove
grease).
Avoid dipping or immers-
ing in alcohol, gasoline,
solvents, etc.
SMC Sheet
Moulding
Compound
180
(356) Alcohol and gasoline are
harmless.
Avoid alkali
TPO Thermoplastic
Olefine 80
(176) Alcohol is harmless.
Gasoline is harmless if applied only
for short time in small amounts.
Most solvents are harm-
less but avoid dipping in
gasoline, solvents, etc.
TPU Thermoplastic
Polyurethane 80
(176) Alcohol is harmless if applied only for
very short time in small amounts (e.g.,
quick wiping to remove grease).
Avoid dipping or immers-
ing in alcohol, gasoline,
solvents, etc.
UP Unsaturated
Polyester 11 0
(233) Alcohol and gasoline are
harmless.
Avoid alkali
* Temperatures higher than those listed here may result in material deforma\
tion during repair.
PLASTIC BODY PARTSPP-3
WhereEverybodyKnowsYourName

Butt Weld
INSTALLATION
Butt Weld
1. Temporarily install the new parts and check thefit of the front door.
BODY PANEL REPLACEMENTRE-33
WhereEverybodyKnowsYourName

FOAMED MATERIAL APPLICATION AREAS
The sections shown in the figure below are
filled with foamed material to provide noise
insullation.
After repairing these sections or their periph-
eries, refill with foamed material.
HINT:1. Use the service holes located on the reverse side of the body panel to refillwith foamed material.
2. When handling foamed material, follow the directions of the material's manufac-
turer.
APPENDIXAP-4
WhereEverybodyKnowsYourName

1. Before temporarily installing the new parts,apply body seater to the wheel arch.
HINT:
1) Apply body sealer about 5 mm (0.20 in.) from the flange, avoiding any oozing.
2) Apply sealer evenly, about 3 - 4 mm (0.12 - 0.16 in.) in diameter.
3) For other sealing points, refer to section AR.
RE 42 BODY PANEL REPLACEMENT-Rear Body Components
INSTALLATION
Butt Weld
Body Sealer
Butt Weld
Body Sealer
about 5 mm
2. Temporarily install the new parts and check thefit of the front door, luggage compartment door
and rear combination light.
3. Apply foamed material to the pillar section.
HINT: For the foamed material application areas, refer to page AP-00.
INSTALLATION DIAGRAM
Describes in detail installation of the new parts involving repair by we\
lding and/or cutting,
but excluding painting.
INSTALLATION GUIDE
Provides additional information to more efficiently help you perform the installation.
SYMBOLS
See page IN-4.
ILLUSTRATION OF WELD POINTS
Weld method and panel position symbols.
See page IN-5.
INTRODUCTIONIN-3
WhereEverybodyKnowsYourName

INSTALLATION
PRE-WELDING MEASUREMENTS
Always take measurements
before installing underbody
or engine components
to insure correct assembly.
After installation, confirm
proper fit.POST-WELDING REFINISH-
ING
1. Always check the welded
spots to insure they are
secure.
2. When smoothing out the weld spots with a disc
grinder, be careful not to
grind off too much as this
would weaken the weld.
WELDING PRECAUTIONS
1. The number of welding spots
should be as follows.
Spot weld: 1.3 x No. of
manufacturer's spots.
Plug weld: More than No. of
manufacturer's plugs.
WRONG
OKAYWRONG
2. Plug welding should be done
with a MIG (Metal Inert Gas)
welder. Do not gas weld or
braze panels at areas other
than specified.
Safety Glass
Body
Measurement
Diagrams
SPOT WELDING PRECAUTIONS
SPOT WELD LOCATIONS
Try to avoid welding over
previous spots. 1. The shape of the welding
tip point has an effect on
the strength of the weld.
2. Always insure that the seams and welding tip are
free of paint.
Old
Spot
Locations New Spot
Locations
Tip Cutter
INTRODUCTIONIN-13
WhereEverybodyKnowsYourName

CHECK AND REPLACEMENT OF
ENGINE COOLANT
1. CHECK ENGINE COOLANT LEVEL AT RESERVOIR TANK
The coolant level should be between the ºLOWº and ºFULLº
lines at low temperature.
If low, check for leaks and add coolant up to the ºFULLº line.
2. CHECK ENGINE COOLANT QUALITY There should be no excessive deposits of rust or scales
around the radiator cap or radiator filler hole, and the coolant
should be free from oil.
If excessively dirty, replace the coolant
3. REPLACE ENGINE COOLANT (a) Remove the radiator cap.
CAUTION: To avoid the danger of being burned, do not
remove it while the engine and radiator are still hot, as
fluid and steam can be blown out under pressure.
(b) Drain the coolant from the radiator drain cock andengine drain plug.
(c) Close the drain cock and plug.
Torque (Engine drain plug):
29 NVm (300 kgf Vcm, 22 ft Vlbf)
(d) Fill the system with coolant.
w Use a good brand of ethylene±glycol base coolant,
mixed according to the manufacturer's direction.
w Using coolant which includes more than 50 %
ethylene±glycol (but not more than 70%) is
recommended.
NOTICE:
w Do not use alcohol type coolant.
w The coolant should be mixed with demineralized water or
distilled water.
Coolant capacity (w/ Heater): M/T 8.5 liters (9.0 US qts, 7.5 Imp. qts)
A/T 8.4 liters (8.9 US qts, 7.4 Imp. qts)
(e) Install the radiator cap.
(f) Start the engine and check for leaks.
(g) Recheck the coolant level and refill as necessary.
±
COOLING SYSTEM Check and Replacement of Engine CoolantCO±5
WhereEverybodyKnowsYourName

(f) Slowly add coolant to water inlet housing until it is full.w Use a good brand of ethylene±glycol base coolant,
mixed according to the manufacturer's directions.
w Using coolant which includes more than 50%
ethylene±glycol (but not more 70%) than is
recommended.
NOTICE:
w Do not use alcohol type coolant.
w The coolant should be mixed with demineralized water or
distilled water.
Capacity (w/ Heater): 10.8 liters (11.4 US qts, 9.5 lmp. qts)
(g) Reinstall a new gasket and filler plug to the water inlethousing.
Torque: 44 N Vm (450 kgf Vcm, 33 ft Vlbf)
(h) Slowly add coolant to reservoir tank until it is full.
(i) Reinstall the radiator cap.
(j) Bleed the cooling system.
w Start the engine, and open the heater water valve.
w Maintain the engine speed at 2,000 rpm, and warm
up the engine.
(k) Check for leaks.
(l) Recheck the coolant level and refill as necessary.
±
COOLIING SYSTEM Check and Replacement of Engine CoolantCO±7
WhereEverybodyKnowsYourName

5. INSPECT WATER TEMPERATURE SENSORUsing an ohmmeter, measure the resistance between the ter-
minals.
Resistance: 1.48±1.58 k
at 80 5C (176 5F)
If the resistance is not as specified, replace the sensor.
6. REINSTALL WATER TEMPERATURE SENSOR (a) Install a new O±ring to the water temperature sensor.
(b) Apply soapy water to the O±ring.
(c) Install the water temperature sensor to the radiator.
Torque: 7.4 N Vm (75 kgf Vcm, 65 in. Vlbf)
(d) Connect the water temperature sensor connector.
7. REFILL WITH ENGINE COOLANT (See page CO±7)
8. REINSTALL ENGINE UNDER COVER
9. RECONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
(A/C High±Pressure Switch)
INSPECTION OF A/C HIGH±PRESSURE
SWITCH
1. DISCONNECT HIGH±PRESSURE SWITCH CONNECTOR
2. INSTALL MANIFOLD GAUGE SET (See AC section)
3. INSPECT HIGH±PRESSURE SWITCH(a) Wh e n th e A/C switch is OFF, ch e ck th a t th e re iscontinuity between terminals 2 and 3. (When the
pressure is 1,226 kPa (12.5 kgf/cm
2, 178 psi) or lower.)
(b) When the A/C switch and blower switch are ON, check
that there is no continuity between terminals 2 and 3.
(When the pressure is 1,520 kPa (15.5 kgf/cm
2, 220 psi)
or higher.)
If continuity is not as specified, replace the switch.
4. REMOVE MANIFOLD GAUGE SET
5. RECONNECT HIGH±PRESSURE SWITCH CONNECTOR
(Solenoid Valve)
(See page CO±36)
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)CO±63
WhereEverybodyKnowsYourName

DESCRIPTION
The emission control systems are installed to reduce the amount of HC, CO, \
and NOx emitted from the en-
gine, and to also prevent the release of evaporated fuel from the gasoline ta\
nk and prevent atmospheric release
of blow±by gas. The system consists of the PCV, EVAP, EGR and TWC.
The function of each system is shown in the following table.
 
System
 
Abbreviation
 
Purpose 
Positive crankcase ventilation
 
PCV
 
Reduces blow±by gas (HC) 
Fuel evaporative emission control
 
EVAP
 
Reduces evaporative HC 
Exhaust gas recirculation
 
EGR
 
Reduces NOx 
Three±way catalyst
 
TWC
 
Reduces HC, CO, and NOx 
Electronic fuel injection*
 
EFI
 
Regulates all engine conditions for   
reduction of exhaust emissions.
Remarks: * For inspection and repair of the EFI system, refer to EFI sec\
tion.
COMPONENTS LAYOUT
EC±2±
EMISSION CONTROL SYSTEMS Description
WhereEverybodyKnowsYourName