COMPRESSION PRESSURE - Measurement of Compression Pressure

EM-73prose procedure

Compression pressure differs between SR20DE and SR20DET.

1
Warm up engine.
2
Turn ignition switch off.
3
Release fuel pressure. Refer to "Releasing Fuel Pressure" in section EF & EC.
4
Remove all spark plugs.
5
Disconnect distributor center cable.
6
Attach a compression tester to No. 1 cylinder.
SEM578D
7
Depress accelerator pedal fully to keep throttle valve wide open.
8
Crank engine and record highest gauge indication.
9
Repeat the measurement on each cylinder as shown above.
Always use a fully-charged battery to obtain specified engine revolution.
10
If cylinder compression in one or more cylinders is low, pour a small amount of engine oil into cylinders through spark plug holes and retest compression.
If adding oil helps compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat. (Refer to S.D.S.) If valve or valve seat is damaged excessively, replace them.
If compression in any two adjacent cylinders is low and if adding oil does not help compression, there is leakage past the gasket surface. If so, replace cylinder head gasket.

	SR20DE	SR20DET
Standard	1,275 (12.75, 13.0, 185)	1,128 (11.28, 11.5, 164)
Minimum	1,079 (10.79, 11.0, 156)	932 (9.32, 9.5, 135)
Difference limit between cylinders	98 (0.98, 1.0, 14)	98 (0.98, 1.0, 14)

Standard

SR20DE1,275 (12.75, 13.0, 185)

SR20DET1,128 (11.28, 11.5, 164)

Minimum

SR20DE1,079 (10.79, 11.0, 156)

SR20DET932 (9.32, 9.5, 135)

Difference limit between cylinders

SR20DE98 (0.98, 1.0, 14)

SR20DET98 (0.98, 1.0, 14)

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