Outline Of Diagnosis

Detect the presence of misfire occurrence. (Revolution fluctuation method)

Monitoring misfire which influences exhaust deterioration (exhaust gas misfire) and catalyst damage is made obligatory by the law. Misfire affecting these two has two patterns below:

• Intermittent misfire (a single cylinder misfires at random times, or different cylinders misfire at random): Exhaust gas misfire

  Every time misfire (a single cylinder misfires every time): Exhaust gas misfire, catalyst damaging misfire

  The following detecting methods are adopted for these detection.

  1. Intermittent misfire: Exhaust gas misfire
     • 180° Interval Difference Method
     • 360° Interval Difference Method
     • 720° Interval Difference Method
  2. Every time misfire: Exhaust gas misfire, catalyst damaging misfire
     • 180° Interval Difference Method
     • 360° Interval Difference Method