Technician A says that a rough idle on a fuel-injected engine can be caused by dirty throttle plates.
Technician B says that the wrong PCV valve could cause the engine to idle roughly. Which technician is correct?

Question

Quizplus · Accepted Answer

Both technicians A and B are correct. Dirty throttle plates can cause a rough idle on a fuel-injected engine by limiting the amount of air that can enter the engine. A worn or wrong PCV valve can cause a rough idle by allowing too much air to enter the engine, disrupting the air/fuel mixture.

Technician a Says That a Rough Idle on a Fuel-Injected