Ignition Timing Inspection

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 powertrain control module (PCM). If it doesn't communicate, go to DLC CIRCUIT TROUBLESHOOTING .
Check for DTCs (see GENERAL TROUBLESHOOTING INFORMATION ). If a DTC is present, diagnose and repair the cause before continuing with this test.
Start the engine. Hold the engine speed at 3, 000 rpm with no load (in N or P) until the radiator fan comes on, then let it idle.
Check the idle speed (see IDLE SPEED INSPECTION ).
Jump the SCS line with the HDS.
Connect the timing light to the exhaust side No. 1 ignition coil harness.

Fig 1: Connecting Timing Light To Exhaust Side No. 1 Ignition Coil Harness
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Aim the light toward the pointer (A) on the cam chain case. Check the ignition timing under a no load condition (headlights, blower fan, rear window defogger, and air conditioner are turned off).
Ignition Timing

102° BTDC (RED mark (B)) at idle in N or P

Fig 2: Aiming Light Toward Pointer On Cam Chain Case
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the ignition timing differs from the specification, check the cam timing. If the cam timing is OK, update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the system works properly, and the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ).
Disconnect the HDS and the timing light.