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 wave form observation (No.1 cylinder - No.4 cylinder, No.2 cylinder - No.3 cylinder). However, wave form 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 pattern is displayed can be difficult. For reference, remember that the wave form pattern of the cylinder attached to the secondary pickup will be displayed as stable.




IGNITION PRIMARY VOLTAGE WAVEFORM CHECK
1. Disconnect the ignition power transistor connector and connect the special tool (harness connector: MB991348) in between. (Connect all the terminals.)
2. Connect the analyzer primary pickup to the ignition power transistor connector terminal 8 when observing the No. 1 - No.4 cylinder group, terminal 1 for the No.2 - No.3 cylinder group.
3. Connect the primary pickup earth terminal.
4. Clamp the spark plug with the trigger pickup.

NOTE:
1. Clamp the spark plug cable for No.1 and No.3 cylinders of the same group with the cylinder that is connected to the primary pickup.
2. The wave pattern of either cylinder in the same group will appear at the left edge of the screen.




STANDARD WAVEFORM




Observation Conditions




Observation Conditions (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:
Height of Zener voltage




ABNORMAL WAVEFORMS EXAMPLES