Exam 27: Ignition System Diagnosis and Service

If the needle on a vacuum gauge drops significantly every two revolutions of the engine, the fault is a ____________________ problem.

Technician A says a loose ignition module mount can cause intermittent misfires or no-start conditions. Technician B says when installing a new ignition module, a small amount of heat conductive grease should be applied to the mounting surfaces. Who is correct?

A "cranks but does not start" problem on a waste spark type EI system is being diagnosed. When a spark tester is connected to each coil and the starter is engaged, there is no spark. Technician A says the crankshaft position sensor could be the problem. Technician B says the PCM could be the problem. Who is correct?

Preignition is the same as detonation.

Waste spark EI systems are being discussed. Technician A says a high-resistance spark plug won't affect the firing of its companion spark plug. Technician B says improper spark plug torque can't cause an engine misfire. Who is correct?

What is Mode #6 data?

Ignition coil testing is being discussed. Technician A uses an ohmmeter to measure primary and secondary resistance. Technician B uses an oscilloscope and a test spark plug to measure maximum coil output voltage. Who is correct?

Spark duration is represented by the length of the spark line and is measured in ____________________.

Crankshaft position sensors (CKP)are _____ type sensors.

While testing a coil in an EI ignition system, Technician A says an infinite reading means that the winding has zero resistance and is shorted. Technician B says the secondary winding in a waste spark (doubled-ended)coil should be checked by connecting the meter across the two secondary terminals. Who is correct?

All ignition system diagnosis should begin with a visual inspection.

An ignition module may be damaged due to a poor electrical ground circuit.

A bad sensor ground may cause the same symptoms as a faulty sensor.

While discussing EI service, Technician A says the crankshaft sensor may be rotated to adjust the basic ignition timing. Technician B says the crankshaft sensor may be moved to adjust the clearance between the pickup coil and reluctor on some EI systems. Who is correct?

The companion cylinder for #1 cylinder on a six-cylinder engine with a firing order of 153624 is cylinder # ____________________.

What are the causes of detonation ?

Which of the following is NOT the location of the ignition module?

Noise symptoms of overly advanced timing include ____________________ or engine knock.

Technician A says large amounts of EMI can collapse the field in a coil and cause a plug to fire. Technician B says poor spark plug cable insulation may cause EMI. Who is correct?

Carbon ____________________ is the formation of a line of carbonized dust between distributor cap terminals or between a terminal and the distributor housing.