Compression Check: Testing and Inspection

Engine Compression Inspection

NOTE: After this inspection, you must reset PGM-FI ECU in the PGM-FI INSPECTION menu with the HDS to cancel ALL INJECTORS STOP and STARTER TEST functions.

1. Allow the engine to reach operating temperature (fan comes on at least twice).

2. Turn the ignition switch to LOCK (0).

3. Connect the HDS to the DLC.

4. Turn the ignition switch to ON (II).

5. Make sure the HDS communicates with the vehicle and the PCM. If it do not communicate, troubleshoot the DLC circuit DLC Circuit Troubleshooting (PGM-FI System).

6. Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.

7. Select STARTER TEST in the PGM-FI INSPECTION menu with the HDS.

8. Turn the ignition switch to LOCK (0).

9. Remove the four intake side ignition coils and the four spark plugs Service and Repair.

10. Attach the compression gauge to the spark plug hole.






11. Step on the accelerator pedal to open the throttle fully, then crank the engine with the starter motor and measure the compression.





12. Measure the compression on the remaining cylinders.





13. If the compression is not within specifications, perform a cylinder leak down test to determine the problem area. Then check the following items, and remeasure the compression:

- Incorrect valve clearance
- Confirmation of cam timing
- Damaged or worn cam lobes
- Looseness of exhaust side spark plug
- Damaged or worn valves and seats
- Damaged cylinder head gasket
- Damaged or worn piston rings
- Damaged or worn piston and cylinder bore

14. Remove the compression gauge from the spark plug hole.

15. Install the four intake side spark plugs and the four ignition coils Service and Repair.

16. Select PGM-FI ECU reset in the PGM-FI INSPECTION menu with the HDS to cancel ALL INJECTORS STOP and STARTER TEST.