Compression Check: Testing and Inspection

1. Warm up engine.
2. Remove all spark plugs. (Exhaust side) Use a suitable plug wrench.





3. Disconnect distributor harness connector.





4. Remove fuse for fuel pump.





5. Attach a suitable compression tester.
6. Depress accelerator pedal to fully open throttle.
7. Crank engine and read gauge indication.
Compression pressure:
kPa (kg/cm2, psi) at 350 rpm
Standard
1,177 (12.0, 171)
Minimum
883 (9.0, 128)
Differential limit between cylinders
98(1.0,14)

8. If cylinder compression in one or more cylinders is low, pour a small amount of engine oil into cylinders through the spark plug holes and retest compression.
^ It adding oil helps the compression pressure, chances are that piston rings are worn or damaged.
^ If pressure stays low, valve may be sticking or seating improperly.
^ If cylinder compression in any two adjacent cylinders is low, and if adding oil does not help the compression, there is leakage past the gasket surface.