Oscilloscope Patterns and Waveforms

IGNITION SECONDARY VOLTAGE WAVEFORM CHECK

MEASUREMENT METHOD
1. Clamp the SECONDARY PICKUP around the spark plug cable.

NOTE:
1. The peak ignition voltage will be reversed when the spark cables No.2 and No.4, or No.1 and No.3 cylinders are clamped.
2. Because of the two-cylinder simultaneous ignition system, the waveforms for two cylinders in each group appear during waveform observation (No.1 cylinder - No.4 cylinder, No.2 cylinder - No.3 cylinder). However, waveform observation is only applicable for the cylinder with the spark plug cable clamped by the secondary pickup.

2. Clamp the spark plug cable with the Trigger pickup.

NOTE:
1. Clamp the trigger pickup to the same spark plug cable clamped by the secondary pickup.
2. Identifying which cylinder waveform is displayed can be difficult. For reference, remember that the waveform of the cylinder attached to the secondary pickup will be displayed as stable.




STANDARD WAVEFORM




Observation Conditions




Observation Condition (The only change from above condition is the pattern selector.)

WAVEFORM OBSERVATION POINTS




Point A:
The height, length and slope of the spark line (refer to abnormal waveform examples 1, 2, 3 and 4) show the following trends.




Point B:
Number of vibrations in reduction vibration section




Point C:
Number of vibrations at beginning of dwell section




Point D:
Ignition voltage height (distribution per each cylinder) shows the following trends.




ABNORMAL WAVEFORMS EXAMPLES