Oil leak – ASE practice questions (VIDEO)

Technician A completed a compression test, noting high readings suggest an exhaust restriction, while Technician B says the test checks volumetric efficiency.

Technician A and Technician B are discussing ways to use fuel trim as a troubleshooting aid. Technician A says that fuel trims that are correcting for a lean condition at high RPM and load conditions indicates a problem in fuel delivery. Technician B says that this condition is caused by a vacuum leak.

Technician A is diagnosing a misfire. He states that a misfire is caused by a fault in the ignition system and that new plugs and coils will repair the problem. Technician B says that a misfire is detected when the ECM detects a variation in crankshaft speed.