Lexus LS400 (2000 year). Service manual — part 74

B09997

Vent Port

Cap

Air

Air Drain Port

EVAP Port

Purge Port

B09998

Air

Air Inlet Port

Air Drain Port

EVAP Port

Purge Port

B09999

Vacuum

Purge Port

Air Inlet Port

B10000

Vacuum

Purge Port

Air Inlet Port

EVAP Port

–

EMISSION CONTROL

EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM

EC–11

1313

(b)

Inspect the charcoal canister operation.
(1)

Plug the vent port with the cap.

(2)

While holding the purge port closed, blow air (1.76
kPa, 18 gf/cm

2

, 0.26 psi) into the EVAP port and

check that air flows from the air drain port.

(3)

While holding the purge port and the air drain port
closed, blow air (1.76 kPa, 18 gf/cm

2

, 0.26 psi) into

the EVAP port and check that air does not flow from
the air inlet port.

(4)

Apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg)
to the purge port, check that the vacuum does not
decrease when the air inlet port is closed, and
check that the vacuum decreases when the air inlet
port is released.

(5)

While holding the air inlet port closed, apply vacuum
(3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the EVAP port
and check that air flows into the purge port.

If operation is not as specified, replace the charcoal canister.

(6)

Remove the hose and cap from vent port.

10.

INSPECT VSV FOR EVAP (See page

SF–69

)

11.

INSPECT VSV FOR CANISTER CLOSED VALVE (CCV)
(See page

SF–76

)

12.

INSPECT VSV FOR PRESSURE SWITCHING VALVE
(See page

SF–77

)

13.

INSPECT VAPOR PRESSURE SENSOR
(See page

SF–82

)

14.

REINSTALL CHARCOAL CANISTER ASSEMBLY

EM09G–02

P20718

CO/HC Meter

–

ENGINE MECHANICAL

CO/HC

EM–1

1183

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

HINT:
All vacuum hoses should be properly connected.
(f)

SFI system wiring connectors fully plugged

(g)

Ignition timing set correctly

(h)

Transmission in neutral range

(i)

Tachometer and CO/HC meter calibrated by hand

2.

START ENGINE

3.

RACE ENGINE AT 2,500 RPM FOR APPROX. 180 SE-
CONDS

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 performing the 2 mode (2,500 rpm and idle) test, follow
the measurement order prescribed by the applicable local regu-
lations.

EM–2

–

ENGINE MECHANICAL

CO/HC

1184

6.

TROUBLESHOOTING

If the CO/HC concentration does not comply with regulations,
perform troubleshooting in the order given below.
See the table below for possible causes, and then inspect and
correct the applicable causes if necessary.

CO

HC

Problems

Causes

Normal

High

Rough idle

1. Faulty ignitions:

Incorrect timing

Fouled, shorted or improperly gapped plugs

2. Incorrect valve clearance

3. Leaky intake and exhaust valves

4. Leaky cylinders

Low

High

Rough idle

(fluctuating HC reading)

1. Vacuum leaks:

PCV hoses

Intake manifold

Throttle body

Brake booster line

2. Lean mixture causing misfire

High

High

Rough idle

(Black smoke from exhaust)

1. Restricted air filter

2.Faulty SFI systems:

Faulty pressure regulator

Defective ECT sensor

Faulty ECM

Faulty injectors

Faulty throttle position sensor

Faulty MAF meter

EM0A1–02

EM6413

Z04007

EM6414

EM–100

–

ENGINE MECHANICAL

CYLINDER BLOCK

1282

INSPECTION

1.

REMOVE GASKET MATERIAL

Using a gasket scraper, remove all the gasket material from the
top surface of the cylinder block.
2.

CLEAN CYLINDER BLOCK

Using a soft brush and solvent, thoroughly clean the cylinder
block.
NOTICE:
If the cylinder is washed at high temperatures, the cylinder
liner sticks out beyond the cylinder block, so always wash
the cylinder block at a temperature of 45

°

or less.

3.

INSPECT TOP SURFACE OF CYLINDER BLOCK FOR
FLATNESS

Using a precision straight edge and feeler gauge, measure the
surface contacting the cylinder head gasket for warpage.

Maximum warpage: 0.07 mm (0.0028 in.)

If warpage is greater than maximum, replace the cylinder block.

4.

INSPECT CYLINDER FOR VERTICAL SCRATCHES

Visually check the cylinder for vertical scratches.
If deep scratches are present, replace the cylinder block.