12 13 ... Normal oscillogram (M, S, W engines only)

Start of ignition voltage peak.
Level of ignition voltage.
Level of combustion voltage.
Period of combustion.
Combustion curve characteristics.
Start of decay process.
Termination oscillations.

Fig 1: Identifying Oscillogram Waveform

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Secondary voltage patterns, beside one another:

Evaluation of ignition voltage peaks at idle speed (this example shows an engine with 4 cylinders).

NOTE: The display of ignition voltage spikes is approx. 20-25% lower than the real value. The uniformity of all cylinders to each other is more important than the height of ignition voltage peaks. Differences of 3000-4000 V are permitted.

Fig 2: Identifying Oscillogram Waveform (Evaluation Of Ignition Voltage Peaks At Idle Speed)

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Evaluation of ignition voltage peaks at increased speed of approx. 2000 rpm (this example shows an engine with 4 cylinders).

Fig 3: Identifying Oscillogram Waveform (Evaluation Of Ignition Voltage Peaks At Increased Speed)

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Secondary voltage diagrams, superimposed:

Evaluation of combustion characteristics curve and decay characteristics at idle speed (this example shows a 4-cylinder engine).

Fig 4: Identifying Secondary Voltage Diagrams (Characteristics At Idle Speed)

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Secondary voltage diagrams, consecutive:

NOTE: Only the major differences in the ignition voltage patterns are revealed by this method of comparison. The identified fault must be allocated to the relevant cylinder using the secondary voltage representation forms next to/on top of each other.

Fig 5: Identifying Secondary Voltage Diagrams (Consecutive)

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