Technician A says that vacuum is high when engine load is high. Technician B says that vacuum is high when an engine is at idle speed and no load. Who is correct?

Question

Quizplus · Accepted Answer

Technician B is correct. When an engine is at idle speed and no load, there is less air entering the engine, which increases the vacuum. When the engine load is high, there is more air entering the engine, which decreases the vacuum.

Technician a Says That Vacuum Is High When Engine Load