Operation CHARM: Car repair manuals for everyone.

Compression Test

TO TEST COMPRESSION:

NOTE: For the most accurate test results, the battery should be fully charged and the engine should be warm.

1. With the ignition off, disable the secondary circuit of the ignition system by disconnecting the harness connector at the coil power stage. Disable the fuel pump by removing the fuel pump fuse (no. 18).
2. Remove the spark plug wires from the spark plugs. Use care to pull on both the wire and the boot at the same time. Label the wires for correct reinstallation.
3. Clean the area around the spark plugs using compressed air. Remove the spark plugs and set them aside in order.
4. Thread the compression tester into the first cylinder's spark plug hole, just tight enough to seal the plug hole.
5. With the transmission in neutral and the throttle held wide open, crank the engine with the starter about 4 to 5 revolutions. The gauge reading should increase with each engine revolution. Record the gauge value.
6. Release the pressure in the tester and remove it from the spark plug hole.
7. Repeat the test for each of the other cylinders. Record the data and compare with the specifications below.
8. Reinstall the spark plugs and torque to 30 Nm (22 ft lb). Reinstall the spark plug wires in their original locations. Reconnect the coil harness connector and the fuel pump fuse.