Compression Check: Testing and Inspection
Engine Compression InspectionNOTE:
- If any DTCs are indicated, go to the appropriate DTC troubleshooting index, and clear them as necessary.
- After this inspection, you must reset the powertrain control module (PCM), using the Honda Diagnostic System (HDS) otherwise the PCM continues to stop the fuel injectors.
1. Warm up the engine to normal operating temperature (cooling fans cycle twice).
2. Turn the ignition switch OFF.
3. Connect the HDS to the data link connector (DLC).
4. On the HDS, select PGM-FI, INSPECTION, then ALL INJECTORS OFF function on the HDS.
5. Remove the six ignition coils.
6. Remove the six spark plugs.
7. Disconnect the throttle actuator control module connector and the MAP sensor connector from the throttle body, then remove the mounting hardware.
8. Attach the compression gauge to a spark plug hole.
9. Crank the engine with the starter motor and measure the compression.
NOTE: Use a fully changed battery, and inspect the compression as quickly as possible to prevent battery drain and heat buildup, which can affect your readings.
Compression Pressure: Above 930 kPa (9.5 kgf/cm2, 135 psi)
10. Perform the same measurement on the remaining cylinders one at a time.
Maximum Variation: Within 200 kPa (2.0 kgf/cm2, 28 psi)
11. If the compression is not within specifications, check the following items, then remeasure the compression.
- Damaged or worn valves and seats
- Damaged cylinder head gaskets
- Damaged or worn piston rings
- Damaged or worn piston and cylinder bore
12. Reinstall the throttle body with a new gasket.
13. Using the HDS, reset the PCM to cancel the ALL INJECTORS OFF function.