06-05-25, 06:10 PM
An additional failure cause I've seen in the past:
The housing of one of the coils had a small crack. At certain RPMs the spark took the shortest way to ground to the nearby frame. Hard to find and to be best observed in the dark (tank removed).
Though my first bet would also be on bad contacts somewhere in the ignition switch cabling..
To eliminate all unknowns and for short testing periods you could connect the coils's positive directly to battery. (The coil's negative is switch to ground by the ECU to create the spark)
The housing of one of the coils had a small crack. At certain RPMs the spark took the shortest way to ground to the nearby frame. Hard to find and to be best observed in the dark (tank removed).
Though my first bet would also be on bad contacts somewhere in the ignition switch cabling..
To eliminate all unknowns and for short testing periods you could connect the coils's positive directly to battery. (The coil's negative is switch to ground by the ECU to create the spark)