Compression Check

Turn the engine OFF.
Remove the powertrain control module (PCM) and the ignition fuse from the instrument panel (I/P) fuse block.
Disable the ignition.
Disable the fuel systems.
Block the throttle plate in open position.
Have an assistant crank the engine through, at least 4 compression strokes, in the testing cylinder.
The lowest reading should not be less than 70 percent of the highest reading.
No cylinder reading should be less than 965 kPa (140 psi).