Engine Compression Inspection

NOTE: After the inspection, you must reset the ECM/PCM. Otherwise, the ECM/PCM will continue to stop the injectors from operating. (See GENERAL TROUBLESHOOTING INFORMATION ).

Warm up the engine to normal operating temperature (cooling fan comes on).
Turn the ignition switch to LOCK (0).
Connect the 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 ECM/PCM. If it does not, 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 four ignition coils and all four spark plugs (see IGNITION COIL REMOVAL/INSTALLATION ).
Attach the compression gauge to the 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 fully, then crank the engine with the starter motor, and measure the compression.
Compression Pressure:

Above 980 kPa (10.00 kgf/cm ² , 142.2 psi)
Measure the compression on the remaining cylinders.
Maximum Variation:

Within 196 kPa (2.00 kgf/cm ² , 28.4 psi)
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 piston rings
- Damaged cylinder head gasket
- Damaged or worn valves and seats
- Damaged or worn piston and cylinder bore
Remove the compression gauge from the spark plug hole.
Install the four spark plugs and the four ignition coils.
Select ECM/PCM reset in the PGM-FI INSPECTION menu (see HDS CLEAR COMMAND ) to cancel the ALL INJECTORS STOP function on the HDS.