Ignition Primary Voltage Wave Pattern Check

MEASUREMENT METHOD
(1) Disconnect the ignition power transistor connector and connect the special tool (Harness connector: MB991348) in between. All terminals should be connected.
(2) When observing the No.1 - No.4 cylinder group. connect the primary pick-up of the analyzer probe to power transistor side connector terminal (13).
For the No.2 - No.5 cylinder group, connect to terminal (12) and for the No.3 - No.6 cylinder group, connect to terminal (11).
(3) Ground the primary pick-up ground terminal.
(4) Clamp the spark plug cable with the trigger pick-up.

NOTE:
(1) Clamp the spark plug cable of cylinder No. 1, No. 3 or No.5 which belongs to the same group as the cylinder to which the primary pick-up is connected.
(2) The waveform of any cylinder in the same group appears from the left side of the screen.

STANDARD WAVEFORM





Observation conditions





Observation conditions (Only PATTERN SELECTOR below changes from the above conditions.)

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 (Refer to Abnormal Waveform Example 5.)





(Point C): Height of Zener voltage





ABNORMAL WAVEFORMS EXAMPLES