12 13... Further fault patterns with evaluation

Evaluation of sparking period and ignition voltage peaks at idling speed.

1. Normal combustion period.
2. Normal ignition voltage peak.

Fig 1: Fault Pattern Of Normal System

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Ignition system is OK.

Long sparking period (1) with low ignition voltage peak (2). Indicates low compression.

Fig 2: View Of Long Sparking Period

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Fluctuating sparking period: Indicates contamination on spark plug (shunt).

Short sparking period (1) with high ignition voltage peak.

Fig 3: View Of Short Sparking Period

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Constant but short sparking period: indicates defective ignition lead.