ignition LEXUS GS400 2000 Service Owners Manual

B01900
CO0AD±03
B00922
ECT
Switch
Connector
B02072
B02073
Ammeter
Battery(+)
(±)
CO±24
± COOLING (2JZ±GE)ELECTRIC COOLING FAN
1562 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ELECTRIC COOLING FAN
ON±VEHICLE INSPECTION
1. CHECK COOLING FAN OPERATION WITH LOW
TEMPERATURE (Below 83°C (181°F))
(a) Turn the ignition switch ON.
(b) Check that the cooling fan stops.
If not, check the cooling fan relay and ECT switch, and check
for a separated connector or severed wire between the cooling
fan relay and ECT switch.
(c) Disconnect the ECT switch connector.
(d) Check that the cooling fan rotates.
If not, check the fuses, radiator fan main relay, cooling fan relay,
cooling fan, and check for a short circuit between the cooling
fan relay and ECT switch.
(e) Reconnect the ECT switch connector.
2. CHECK COOLING FAN OPERATION WITH HIGH
TEMPERATURE (Above 93°C (199°F))
(a) Start the engine, and raise coolant temperature to above
93°C (199°F).
HINT:
Coolant temperature is the detected value by the ECT switch
on the radiator lower tank.
(b) Check that the cooling fan rotates.
If not, replace the ECT switch.
3. INSPECT COOLING FANS
(a) Disconnect the cooling fan connector.
(b) Connect battery and ammeter to the cooling fan connec-
tor.
(c) Check that the cooling fan rotates smoothly, and check
the reading on the ammeter.
Standard amperage: 8.5 ± 11.5 A at 20°C (68°F)
(d) Reconnect the cooling fan connector.

EM0D0±01
A00982
CO/HC Meter
± ENGINE MECHANICAL (2JZ±GE)CO/HC
EM±1
1355 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
CO/HC
INSPECTION
HINT:
This check is used only to determine whether or not the idle
CO/HC complies with regulations.
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
(f) SFI system wiring connectors fully plugged
(g) Ignition timing checked correctly
(h) Transmission in neutral position
(i) Tachometer and CO/HC meter calibrated by hand
2. START ENGINE
3. RACE ENGINE AT 2,500 RPM FOR APPROX. 180
SECONDS
4. INSERT CO/HC METER TESTING PROBE AT LEAST
40 cm (1.3 ft) INTO TAILPIPE DURING IDLING
5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT
IDLE AND/OR 2,500 RPM
HINT:
When doing the 2 mode (2,500 rpm and idle) test, follow the
measurement order prescribed by the applicable local regula-
tions.

EM±2
± ENGINE MECHANICAL (2JZ±GE)CO/HC
1356 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.
(a) Check heated oxygen sensors operation.
(See page DI±44)
(b) See the table below for possible causes, and then inspect
and correct the applicable causes if necessary.
HCCOPhenomenonCauses
HighNormalRough idle1. Faulty ignitions:

Incorrect timing

Fouled, shorted or improperly gapped plugs

Open or crossed high±tension cords
2. Incorrect valve clearance
3. Leaky intake and exhaust valves
4. Leaky cylinder
HighLowRough idle
(Fluctuating HC reading)1. Vacuum leaks:

PCV hose

Intake manifold

Throttle body

Cylinder head gasket
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)1. Restricted air filter
2. Plugged PCV valve
3. Faulty SFI systems:

Faulty pressure regulator

Faulty ECM

Faulty injector

Faulty throttle position sensor

Faulty mass air flow meter

B01982
LEXUS
Hand±Held
Tester
EM0D3±02
A02667
TC
E1 SST
DLC1
A02668
Igniter
White Lead Wire
A02637
EM±12
± ENGINE MECHANICAL (2JZ±GE)IGNITION TIMING
1366 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
IGNITION TIMING
INSPECTION
1. WARM UP ENGINE
Allow the engine to warm up to normal operating temperature.
2. CONNECT LEXUS HAND±HELD TESTER OR OBDII
SCAN TOOL
(a) Connect the LEXUS hand±held tester or OBDII scan tool
to the DLC3.
(b) Please refer to the LEXUS hand±held tester or OBDII
scan tool operator's manual for further details.
3. CONNECT TIMING LIGHT TO ENGINE
4. CHECK IDLE SPEED (See page EM±13)
5. INSPECT IGNITION TIMING
(a) Using SST, connect terminals TC and E1 of the DLC1.
SST 09843±18020
(b) Connect the timing light clip to the white lead wire.
NOTICE:
Use a timing light that can detect the primary signal.
(c) Using a timing light, check the ignition timing.
Ignition timing: 10 ± 2° BTDC @ idle
(Transmission in neutral position)
(d) Remove the SST from the DLC1.
6. FURTHER CHECK IGNITION TIMING
Ignition timing: 6 ± 16° BTDC @ idle
(Transmission in neutral position)
HINT:
The timing mark moves in a range between 6° and 16°.
7. DISCONNECT TIMING LIGHT FROM ENGINE
8. DISCONNECT LEXUS HAND±HELD TESTER OR
OBDII SCAN TOOL

EM0D4±01
± ENGINE MECHANICAL (2JZ±GE)IDLE SPEED
EM±13
1367 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
IDLE SPEED
INSPECTION
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
(f) SFI system wiring connectors fully plugged
(g) Ignition timing checked correctly
(h) Transmission in neutral position
2. CONNECT LEXUS HAND±HELD TESTER OR OBDII SCAN TOOL (See page EM±12)
3. INSPECT IDLE SPEED
(a) Race the engine speed at 2,500 rpm for approx. 90 seconds.
(b) Check the idle speed.
Idle speed: 700 ± 50 rpm
If the idle speed is not as specified, check the throttle body.
4. DISCONNECT LEXUS HAND±HELD TESTER OR OBDII SCAN TOOL

A11124
Ignition Coils and
High±Tension Cord
Assembly
GasketNo.2 Cylinder Head Cover
Camshaft Timing Oil Control ValveExhaust Camshaft
No.1 Camshaft Bearing Cap
Gasket
No.1 Cylinder Head Cover
No.2 Camshaft Bearing Cap x 6
x 24 x 6
20 (200, 15)
20 (200, 15)
Intake Camshaft
 O±Ring
 GasketOil Control Valve Filter
x 14 No.3 Camshaft Bearing Cap
No.1 Oil Pipe
See page EM±52
1st 35 (350, 25)
2nd Turn 90°
3rd Turn 90°
Heater Hose
55 (550, 41)
Union Bolt
18 (180, 13)Spark Plug
 Oil Seal
No.4 Timing Belt Cover
Camshaft Timing Pulley
Cylinder Head Assembly
Intake Manifold Assembly
Manifold Stay
 Cylinder Head Gasket
 Gasket
x 7
81 (810, 60)
15 (150, 11)
8.0 (80, 71 in.´lbf)
N´m (kgf´cm, ft´lbf) : Specified torque
 Non±reusable partx 12
28 (280, 21)
Starter Wire
Straight
Screw Plug
Timing Belt
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±31
1385 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

EM0D1±05
A11132
Compression Tester
± ENGINE MECHANICAL (2JZ±GE)COMPRESSION
EM±3
1357 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPRESSION
INSPECTION
HINT:
If there is lack of power, excessive oil consumption or poor fuel
economy, measure the compression pressure.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to normal operating temperature.
2. REMOVE ENGINE COVER
Remove the 4 nuts and engine cover.
3. DISCONNECT IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±7)
4. REMOVE SPARK PLUGS
5. DISCONNECT INJECTOR CONNECTORS
6. CHECK CYLINDER COMPRESSION
(a) Insert a compression tester into the spark plug hole.
(b) While cranking the engine, measure the compression
pressure.
HINT:
Always use a fully charged battery to obtain engine revolutions
of 250 rpm or more.
(c) Repeat steps (a) through (b) for each cylinder.
NOTICE:
This measurement must be done in as short a time as pos-
sible.
Compression:
1,324 kPa (13.5 kgf/cm
2, 192 psi) or more
Minimum pressure:
1,079 kPa (11.0 kgf/cm
2, 156 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 14 psi) or less
(d) If the cylinder compression in 1 or more cylinders is low,
pour a small amount of engine oil into the cylinder through
the spark plug hole and repeat steps (a) through (b) for
the cylinder with low compression.

If adding oil helps the compression, it is likely that
the piston rings and/or cylinder bore are probably
worn or damaged.

If pressure stays low, a valve may be sticking or
seating improper, or there may be leakage past the
gasket.

EM±4
± ENGINE MECHANICAL (2JZ±GE)COMPRESSION
1358 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
7. RECONNECT INJECTOR CONNECTORS
HINT:
The Nos.1, 3, 5 injector connectors and dark gray, and the
Nos.2, 4, 6 injector connectors are brown.
8. REINSTALL SPARK PLUGS
9. RECONNECT IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±9)
10. INSTALL ENGINE COVER
Install the engine cover with the 4 nuts.

A02819
A09752
A02735
EM±34
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
1388 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(b) Remove the 3 bolts and nuts holding the front exhaust
pipe to the exhaust manifold.
(c) Remove the 2 bolts and pipe support bracket.
(d) Disconnect the front exhaust pipe from the exhaust man-
ifold, and remove the 2 gaskets.
10. REMOVE EXHAUST MANIFOLD
(a) Disconnect the 3 heated oxygen sensor connectors and
clamp.
(b) Remove the clamp and case clamp.
(c) Using a 14 mm deep socket wrench, remove the 8 nuts,
exhaust manifold and 2 gaskets.
11. REMOVE WATER BYPASS OUTLET AND NO.1
WATER BYPASS PIPE (See page CO±11)
12. REMOVE THROTTLE BODY AND INTAKE AIR
CONNECTOR ASSEMBLY (See page EM±5)
13. REMOVE OIL DIPSTICK AND GUIDE FOR ENGINE
(See page LU±6)
14. REMOVE OIL DIPSTICK AND GUIDE FOR A/T
(See page EM±62)
15. REMOVE AIR INTAKE CHAMBER (See page SF±46)
16. REMOVE VACUUM CONTROL VALVE SET AND NO.2
VACUUM PIPE
(a) Disconnect the VSV connector for the ACIS.
(b) Remove the 3 nuts, vacuum control valve set and No.2
vacuum pipe.
(c) Disconnect the engine wire clamp from the clamp bracket
of the No.2 vacuum pipe.
17. REMOVE NO.3 TIMING BELT COVER
18. REMOVE IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±7)
19. REMOVE SPARK PLUGS

A02638
A02651
A02664
EX
IN135
24
135
24 1 1
EM±6
± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
1360 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. REMOVE NO.3 TIMING BELT COVER
Using a 5 mm hexagon wrench, remove the 4 bolts, oil filler cap,
timing belt cover and gasket.
6. REMOVE IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±7)
7. REMOVE SPARK PLUGS
8. DISCONNECT ENGINE WIRE FROM CYLINDER HEAD
COVERS
9. REMOVE CYLINDER HEAD COVERS
(See page EM±33)
10. SET NO.1 CYLINDER TO TDC/COMPRESSION
(a) Turn the crankshaft pulley and align its groove with the
timing 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 pul-
leys are aligned with the timing marks of the No.4 timing
belt cover.
If not, turn the crankshaft 1 revolution (360°).
11. INSPECT VALVE CLEARANCE
(a) Check only those valves indicated in the illustration.

Using a feeler gauge, measure the clearance be-
tween the valve lifter and camshaft.

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):
Intake0.15 ± 0.25 mm(0.006 ± 0.010 in.)
Exhaust0.25 ± 0.35 mm (0.010 ± 0.014 in.)
(b) Turn the crankshaft pulley 1 revolution (360°), and align
the groove with the timing mark º0º of the No.1 timing belt
cover.