Ignition Timing: Testing and Inspection

Ignition Timing Inspection

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2).
2. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or Neutral) until the radiator fan comes on, then let it idle.
3. Check the idle speed.
4. Jump the SCS line with the HDS.
5. Connect the timing light to the No. 1 ignition coil harness.






6. Aim the light toward the pointer (A) on the timing belt cover. Check the ignition timing under a no load condition (headlights, blower fan, rear window defogger, and air conditioner are turned off).






7. If the ignition timing differs from the specification, check the cam timing. If the cam timing is OK, update the powertrain control module (PCM). If it does not have the latest software, or substitute a known-good PCM, then recheck. If the system works properly, and the PCM was substituted, replace the original PCM.
8. Disconnect the HDS and the timing light.