The firing lines on an oscilloscope are all abnormally low. Technician A says the problem could be a faulty coil. Technician B says the problem could be a lean air/fuel mixture. Who is correct?
A)A only
B)B only
C)both A and B
D)neither A nor B

Question

Quizplus · Accepted Answer

A faulty coil can cause weak or low firing lines on an oscilloscope due to insufficient spark energy. A lean air/fuel mixture would not typically cause low firing lines.

The Firing Lines on an Oscilloscope Are All Abnormally Low