Compression Check - Toyota Land Cruiser 1988 Repair Manual

EM-10
ENGINE MECHANICAL- Compression Check
COMPRESSION CHECK
NOTE: If there is lack of power, excessive oil consump-
tion or poor fuel economy, measure the cylinder com-
pression pressure.
1. WARM UP AND STOP ENGINE
2. DISCONNECT DISTRIBUTOR CONNECTOR
3. DISCONNECT COLD START INJECTOR
CONNECTOR
4. REMOVE SPARK PLUGS
5. CHECK CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) Fully open the throttle valve.
(c) While cranking the engine with the starter, measure
the compression pressure.
NOTE: Always use a fully charged battery to obtain
engine revolutions of more than 200 rpm.
CAUTION: This measurement must be done for
as short time as possible.
(d) Repeat steps (a) through (c) for each cylinder.
Compression pressure:
10.5 kglcm
2
(149 psi, 1,030 kPa) or more
Minimum pressure:
8.0 kglcm
2
(114 psi, 785 kPa)
Difference between each cylinder:
0.5 kg I cm
2
(7 psi. 49 kPa) or less
(e) 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, probably the
piston rings and I or cylinder bore are worn or
damaged.
• If pressure stays low, a valve may be sticking or
seated improperly, or there may be leakage past
the gasket surface.
6. REINSTALL SPARK PLUGS
Torque: 180 kg-em (13 ft-lb, 18 N·m)
7. RECONNECT COLD START INJECTOR
CONNECTOR
8. RECONNECT DISTRIBUTOR CONNECTOR