EM0KR−04
−
ENGINE MECHANICAL COMPRESSION
EM−3
506
Author: Date:
1996 LAND CRUISER (RM451U)
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. DISCONNECT DISTRIBUTOR CONNECTOR
3. REMOVE SPARK PLUGS (See page IG−1 )
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:
1,176 kPa (12.0 kgf/cm
2, 171 psi) or more
Minimum pressure: 883 kPa (9.0 kgf/cm
2, 128 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 14 psi) or less
If the cylinder compression in one 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.
If adding oil helps the compression, it is likely that
the piston rings and/or cylinder bore are worn or
damaged.
If pressure stays low, a valve may be sticking or
seating is improper, or there may be leakage past
the gasket.
5. REINSTALL SPARK PLUGS (See page IG−1 )
6. RECONNECT DISTRIBUTOR CONNECTOR
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Version 1.11 - 03/16/2010
