Exam 27: Ignition System Diagnosis and Service

Identify various drivability problems that an ignition system misfire can cause.

An occasional glow around a spark plug cable, known as a ____________________ effect, is not harmful but indicates that the cable should be replaced.

Mode ____________________ scan tool data displays the test values stored at the time a particular monitor was completed. This data can be useful in engine misfire diagnosis.

While discussing an ignition problem displayed on a scope primary ignition pattern, Technician A says a worn distributor drive gear can cause an erratic transistor ON signal. Technician B says if there are erratic voltage spikes at the transistor ON signal, the ignition module may be faulty. Who is correct?

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?

What problems typically cause DTCs that indicate a misfire at an individual cylinder (P0301, P0302, P0303, etc.)?

Only engines equipped with a ____________________ may need to have their ignition timing set or adjusted.

Name the three categories of stress tests used to check for intermittent ignition component problems.

An ohmmeter connected to the leads of a pickup coil in a DI ignition system reads 14 ohms of resistance. The reading indicates that the pickup coil ______.

EMI can be produced by the vehicle's primary ignition circuit.

On an oscilloscope, which section ends with the primary coil current off signal?

Some manufacturers recommend the use of special heat-conductive ____________________ grease between the control unit [ignition module] and its mounting surface.

Technician A says a fouled spark plug can cause a misfire. Technician B says a bad coil can cause a misfire. Who is correct?

Insufficient timing advance or retarded timing at higher engine speeds could cause hesitation and poor fuel economy.

To minimize EMI interference, sensor wires should be routed away from _____.

If a distributor cap or rotor has a mild buildup of dirt or corrosion, it should be ____________________.

Test equipment for checking the primary circuit is being discussed. Technician A says a logic probe can be used. Technician B says a DMM can be used. Who is correct?

If a vacuum gauge shows a low but steady vacuum when the engine is at idle, the problem is a noncommon type.

Detonation can cause physical damage to the pistons, valves, bearings, and spark plugs.