In EI systems using one ignition coil for every two cylinders, Technician A says two plugs fire at the same time, with one wasting the spark on the exhaust stroke. Technician B says one plug fires in the normal direction and the other in reversed polarity. Who is correct?
A)A only
B)B only
C)both A and B
D)neither A nor B

Question

Quizplus · Accepted Answer

In Electronic Ignition (EI) systems that use one ignition coil for every two cylinders, both statements are correct. Two plugs do fire at the same time, with one spark being wasted on the exhaust stroke (waste spark system), and one plug fires in the normal direction while the other fires in reversed polarity. This design is used to simplify the ignition system and reduce the number of required coils.

In EI Systems Using One Ignition Coil for Every Two