Technician A says if the EVAP system is purging vapors from the charcoal canister while the engine is idling, rough engine operation will occur. Technician B says the system should not have more than 0.5 liter of flow during the 240 seconds of an I/M 240 test. Who is correct?

Question

Quizplus · Accepted Answer

Technician A is correct because if the EVAP system purges vapors from the charcoal canister while the engine is idling, it can introduce an excessive amount of fuel vapor into the engine. This can disrupt the air-fuel mixture balance, leading to rough engine operation or stalling. Technician B's statement about the specific flow rate during an I/M 240 test is not a standard specification for evaluating EVAP system performance, making it incorrect.

Technician a Says If the EVAP System Is Purging Vapors