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Engine Compression Inspection

NOTE: After this inspection, you must reset the ECM/PCM (see IF THE MIL DID NOT STAY ON ). Otherwise the ECM/PCM will continue to stop the injectors from operating.
  1. Warm up the engine to normal operating temperature (cooling fan comes on).
  2. Turn the ignition switch to LOCK (0).
  3. Connect the HDS to the DLC (see step 2 on GENERAL TROUBLESHOOTING INFORMATION ).
  4. Turn the ignition switch to ON (II).
  5. Make sure the HDS communicates with the vehicle and the ECM/PCM. If it does not communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
  6. Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.
  7. Turn the ignition switch to LOCK (0).
  8. Remove the four ignition coils and the four spark plugs (see IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION ).
  9. Attach the compression gauge to the spark plug hole.
    Fig 1: Attaching Compression Gauge To Spark Plug Hole
    G06949364Courtesy of AMERICAN HONDA MOTOR CO., INC.
  10. Turn the battery module switch OFF (see DISCONNECTING THE IMA MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR ).
  11. Step on the accelerator pedal to open the throttle fully, then crank the engine with the starter motor and measure the compression.

    Compression Pressure 

    Above: 980 kPa (9.99 kgf/cm 2  , 142.1 psi) 

  12. Measure the compression on the remaining cylinders.

    Maximum Variation: 

    Within 200 kPa (2.04 kgf/cm 2  , 29.0 psi) 

  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
    • 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 spark plugs and the four ignition coils (see IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION ).
  16. Select ECM/PCM reset (see IF THE MIL DID NOT STAY ON ) in the PGM-FI INSPECTION menu to cancel ALL INJECTORS STOP with the HDS.
  17. Turn the battery module switch ON (see DISCONNECTING THE IMA MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR ).
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