Technician A says that during a power balance test, the cylinder that causes the biggest RPM drop is the weak cylinder. Technician B says that if one spark plug wire is grounded out and the engine speed does not drop, a weak or dead cylinder is indicated. Which technician is correct?

Question

Quizplus · Accepted Answer

Technician B is correct because if grounding out a spark plug wire does not cause an RPM drop, it indicates that the cylinder is already weak or dead. Technician A is incorrect because the biggest RPM drop indicates a strong cylinder, not a weak one.

Technician a Says That During a Power Balance Test, the Cylinder