Engine Compression Inspection

NOTE: After the inspection, you must reset the powertrain control module (PCM). Otherwise, the PCM will continue to stop the fuel injectors from operating.

Warm up the engine to normal operating temperature (cooling fan comes on).
Turn the ignition switch to LOCK (0).
Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 on GENERAL TROUBLESHOOTING INFORMATION ).
Turn the ignition switch to ON (II).
Make sure the HDS communicates with the vehicle and the PCM. If it does not communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.
Turn the ignition switch to LOCK (0).
Remove the six ignition coils and six spark plugs (see IGNITION COIL REMOVAL/INSTALLATION ).
Attach the compression gauge to a spark plug hole.

Fig 1: Attaching Compression Gauge To Spark Plug Hole
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Step on the accelerator pedal to open the throttle plate fully, then crank the engine with the starter motor, and measure the compression.
Compression Pressure:

Above 930 kPa (9.5 kgf/cm ² , 135 psi)
Measure the compression on the remaining cylinders.
Maximum Variation:

Within 200 kPa (2.0 kgf/cm ² , 28 psi)
If the compression is not within specifications, check the following items, then re-measure 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
Remove the compression gauge from the spark plug hole.
Install the six spark plugs and the six ignition coils (see IGNITION COIL REMOVAL/INSTALLATION ).
Select PCM reset (see HDS CLEAR COMMAND ) in the PGM-FI INSPECTION menu to cancel the ALL INJECTORS STOP on the HDS.