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Engine Compression

Check engine compression with engine at normal operating temperature and specified cranking speed, all spark plugs removed, and throttle wide open. Release fuel pressure by removing fuel pump fuse (located in fuse block) and operate engine until it stalls. Crank engine another 2-3 times to release residual pressure.

Disconnect distributor harness connector. Crank engine at least 6 revolutions to determine engine compression. Compression reading should be as specified. See COMPRESSION SPECIFICATIONS  table.

COMPRESSION SPECIFICATIONS

Application Specification
2.0L (G20)
Compression Ratio 9.5:1
Normal Compression Pressure 178 psi (12.5 kg/cm2 )
Minimum Compression Pressure 149 psi (10.5 kg/cm2 )
Maximum Variation Between Cylinders 14 psi (1 kg/cm2 )
3.0L (M30)
Compression Ratio 9.0:1
Normal Compression Pressure 173 psi (12 kg/cm2 )
Minimum Compression Pressure 128 psi (9 kg/cm2 )
Maximum Variation Between Cylinders 14 psi (1 kg/cm2 )