Ignition Timing: Testing and Inspection

Ignition Timing Inspection

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) and check for DTCs. If a DTC is present, diagnose and repair the cause before inspecting the ignition timing.
2. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or Neutral) until the radiator fan comes on, then let it idle.
3. Check the idle speed.
4. Select "SCS" mode using the HDS.




5. Connect the timing light to the service loop.




6. Aim the light toward the pointers (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).
7. If the ignition timing differs from the specification, check the cam timing. If the cam timing is OK, update the engine control module (ECM)/ powertrain control module (PCM) if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the system works properly, and the ECM/PCM was substituted, replace the original ECM/PCM.
8. Turn the ignition switch OFF.
9. Disconnect the HDS and the timing light.