Exam 27: Ignition System Diagnosis and Service

Possible causes for a no-start condition on a coil-over-plug EI engine are being discussed. Technician A says a faulty crankshaft sensor may prevent the engine from starting. Technician B says a shorted ignition coil may be the cause. Who is correct?

The reluctor (or pole piece)of a magnetic pulse generator should be replaced as a maintenance item when engine spark plugs are renewed.

The height of the ____________________ line in a secondary oscilloscope pattern represents the amount of voltage needed to initiate a spark across the spark plug gap.

Most engines have a spark duration of approximately _____ milliseconds.

Describe how to test the integrity of a suspect electrical connection.

What basic tools are used when checking a Hall-effect sensor?

Spark plug firing voltage should normally be ______.

Technician A removes plug wires by grasping the spark plug boot and gently twisting it off. Technician B uses a 13/16 in. deep thinwall socket to remove spark plugs. Who is correct?

Usually an engine is timed so that the number 1 spark plug fires several degrees _____.

Damaged spark plug threads in an aluminum cylinder head cannot be repaired. The head must be replaced if the threads are damaged.

Identify the appearance of a normal spark plug.

During a coil output test, the firing line shown on the oscilloscope pattern should exceed ______ volts.

Describe how to quick-check a knock sensor.

A defective EI coil may cause cylinder misfiring.

An oscilloscope shows electrical ____________________ changes over a given period of time.

Which of the following is not a common cause of preignition?

The dwell period on a modern electronic ignition system ______.

Name the three types of secondary circuit trace patterns available on an oscilloscope.

Describe a cylinder performance (balance)test.

The slope of the spark line is a good indication of the ____________________.