Measurement of Compression Pressure
1. Warm up engine.
2. Turn ignition switch OFF.
3. Release fuel pressure.
Refer to EC section (ªFuel Pressure Releaseº, ªBASIC SER-
VICE PROCEDUREº).
4. Remove all spark plugs.
lClean area around the plug with compressed air before
removing the spark plug.
5. Disconnect camshaft position sensor harness connector at
the distributor.
6. Disconnect all fuel injector harness connectors.
7. Attach a compression tester to No. 1 cylinder.
8. Depress accelerator pedal fully to keep throttle valve wide
open.
9. Crank engine and record highest gauge indication.
10. Repeat the measurement on each cylinder as shown above.
lAlways use a fully-charged battery to obtain specified
engine speed.
Compression pressure: kPa (bar, kg/cm
2, psi)/rpm
Standard
1,226 (12.26, 12.5, 178)/300
Minimum
1,030 (10.30, 10.5, 149)/300
Difference limit between cylinders
98 (0.98, 1.0, 14)/300
11. If compression in one or more cylinders is low:
a. Pour a small amount of engine oil into cylinders through
spark plug holes.
b. Retest compression.
lIf adding oil improves cylinder compression, piston
rings may be worn or damaged. If so, replace piston
rings after checking piston.
lIf pressure stays low, a valve may be sticking or seating
improperly. Inspect and repair valve and valve seat.
(Refer to SDS, EM-2049 and EM-2051.) If valve or valve
seat is damaged excessively, replace it.
lIf compression stays low in two cylinders that are next
to each other:
a. The cylinder head gasket may be leaking, or
b. Both cylinders may have valve component damage.
Inspect and repair as necessary.
12. Reconnect fuel pump fuse, all fuel injector harness
connectors, and the camshaft position sensor harness con-
nector at the distributor, and then reinstall spark plugs.
SEF215P
SEM486D
COMPRESSION PRESSUREKA24DE
EM-2010
