Toyota TERCEL 1985 Repair Manual page 37

EM-6
ENGINE MECHANICAL - Compression Check
COMPRESSION CHECK
NOTE:
tion or poor fuel milage after engine tune up, measure the
cylinder compression pressure.
1. W A R M UP ENGINE
2. REMOVE FOUR SPARK PLUGS
MEASURE CYLINDER COMPRESSION PRESSURE
(a)
(b)
(c)
NOTE:
at least 250 rpm can be attained.
(d)
Compression pressure:
Minimum pressure:
Difference between each cylinder:
(e)
If there is lack of power, excessive oil consump-
Irísert a compression gauge into the spark plug hole.
Fully open the throttle.
While cranking the engine with the starter motor,
measure the compression pressure.
Always use a fully charged battery to insure that
Repeat steps (a) through (c) for each cylinder.
2
12.5 kg/cm (178 psi, 1,226 kPa)
2
9 kg/cm (128 psi, 883 kPa)
2
1.0 kg/cm (14 psi, 98 kPa) or less
If compression of one or more cylinders is low, pour a
small amount of engine oil into that cylinder through
the spark plug hole and repeat steps (a) through (c)
for the cylinder with low compression.
• If adding oil helps the compression, chances are
that the pistón rings and/or cylinder bore are worn
or damaged.
• If pressure remains low, a valve may be sticking or
seated improperly, or there may be leakage past
the gasket.