How to perform a compression test (From my 1991 FSM page EM-12, SR20DE US spec engine)

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EM-12, SR20DE US spec engine)

Measurement of Compression Pressure
1. Warm up engine
2. Turn ignition switch off
3. Release fuel pressure
4. Remove all spark plugs
5. Disconnect distributor center cable.
6. Attach a compression tester to No. 1 Cylinder
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.

    Compression pressure: kPa (kg/cm^2, psi)/300rpm
    Standard 1,226 (12.5, 178)
    Minimum 1,030 (10.5, 149)
    Difference limit between cylinders 98 (1.0, 14)

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.  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.

Dave