EM03T–02
S04507
CO/HC Meter
–ENGINE MECHANICALCO/HC
EM–1
921Authorr:Datee:
2001 LEXUS ES300 (RM831U)
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 check 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 (idle and 2,500 rpm) test, these mea-
surement order prescribed by the applicable local regulations.
EM–2
–ENGINE MECHANICALCO/HC
922Authorr:Datee:
2001 LEXUS ES300 (RM831U)
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.
See the table below for possible causes, and then inspect and
correct the applicable causes if necessary.
COHCProblemsCauses
NormalHighRough idle1. Faulty ignitions:
jIncorrect timing
jFouled, shorted or improperly gapped plugs
2. Incorrect valve clearance
3. Leaky intake and exhaust valves
4. Leaky cylinders
LowHighRough idle
(Fluctuating HC reading)
1. Vacuum leaks:
jPCV hoses
jIntake manifold
jAir intake chamber
jThrottle body
jIAC valve
jBreak booster line
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)
1. Restricted air filter
2. Plugged PCV valve
3. Faulty SFI systems:
jFaulty pressure regulator
jDefective ECT sensor
jFaulty ECM
jFaulty injectors
jFaulty throttle position sensor
jFaulty MAF meter
EM03U–02
P19471Compression Gauge
–ENGINE MECHANICALCOMPRESSION
EM–3
923Authorr:Datee:
2001 LEXUS ES300 (RM831U)
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 IGNITION COILS (See page IG–5)
3.REMOVE SPARK PLUGS
Using a 16 mm plug wrench, remove the 6 spark plugs.
4.CHECK CYLINDER COMPRESSION PRESSURE
(a)Insert a compression gauge into the spark plug hole.
(b)Fully open the throttle.
(c)While cranking the engine, measure the compression
pressure.
HINT:
Always use a fully charged battery to obtain engine speed of
250 rpm or more.
(d)Repeat steps (a) through (c) for each cylinder.
NOTICE:
This measurement must be done in as short a time as pos-
sible.
Compression pressure:
1,500 kPa (15.3 kgf/cm2, 218 psi)
Minimum pressure: 1,000 kPa (10.2 kgf/cm2, 145 psi)
Difference between each cylinder:
100 kPa (1.0 kgf/cm2, 15 psi) or less
(e)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 (c) for
cylinders with low compression.
jIf adding oil helps the compression, it is likely that
the piston rings and/or cylinder bore are worn or
damaged.
jIf pressure stays low, a valve may be sticking or
seating is improper, or there may be leakage past
the gasket.
5.REINSTALL SPARK PLUGS
6.INSTALL IGNITION COILS (See page IG–5)
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