Air intake system hydrocarbon trap purging

摘要

Methods and systems for purging a hydrocarbon trap in an engine intake in a vehicle are disclosed. In one example approach, a method comprises during an engine off condition, operating a pump in a purge line coupled to a fuel vapor canister in an emission control system to deliver fuel stored in a hydrocarbon trap in an intake of the engine to the fuel vapor canister.

主权项

1. A method for a vehicle with an engine, comprising:
during an engine off condition including a sealed fuel tank holding a vacuum below a threshold, operating a pump in a purge line coupled to a fuel vapor canister in an emission control system to deliver fuel stored in an adsorbent in a hydrocarbon trap in an intake of the engine to the fuel vapor canister; responsive to the engine off condition including a fuel tank vacuum above the threshold, closing a vent valve disposed in a vent path of the fuel vapor canister; opening an isolation valve coupled between the fuel tank and the fuel vapor canister; opening a throttle in the intake of the engine; maintaining the pump in an inactive state; opening a purge valve in the purge line; and applying the fuel tank vacuum to the engine intake, thereby purging the fuel stored in the adsorbent in the hydrocarbon trap.