A secondary ignition oscilloscope pattern is being analyzed. The voltage spikes of cylinders #1, #2, and #3 are 9 to 12 kV while cylinder #4 is 35 kV. What is the most likely cause of this?
A) open plug wires for cylinders #1, #2, and #3
B) shorted spark plug
C) grounded plug wires
D) open plug wire for cylinder #4

Question

Quizplus · Accepted Answer

The voltage spike for cylinder #4 is significantly higher than the other cylinders, indicating a problem with the ignition system specifically on that cylinder. An open plug wire for cylinder #4 is the most likely cause, as it would result in a loss of voltage to that cylinder which would cause the secondary ignition voltage to increase.

A Secondary Ignition Oscilloscope Pattern Is Being Analyzed