| 主权项 |
1. A system for an engine with a fuel vapor recovery system, comprising:
a fuel vapor canister; a restriction valve disposed in a purge flow path between storage material in the fuel vapor canister; an atmosphere vent coupled to the fuel vapor canister and a vent valve disposed therein; a purge conduit coupled to the fuel vapor canister and an intake of the engine; a sensor arranged in the purge conduit; and a controller configured to:
initiate a fuel vapor purging event, including adjusting a duty-cycle of a pump in the purge conduit to provide a first amount of vacuum to the fuel vapor canister and adjusting the restriction valve to provide a first amount of flow restriction between the storage material in the fuel vapor canister;determine, based on input from the sensor, an amount of fuel vapor purged from the fuel vapor canister;if the amount of fuel vapor purged from the fuel vapor canister is less than a first threshold, adjust the duty-cycle of the pump to increase an amount of vacuum provided to the fuel vapor canister to a second, higher amount of vacuum while maintaining the first amount of flow restriction between the storage material in the fuel vapor canister; andafter adjusting the duty-cycle of the pump, determine, based on input from the sensor, the amount of fuel vapor purged from the fuel vapor canister, and if the amount of fuel vapor purged from the fuel vapor canister is less than a second threshold, adjust the restriction valve to increase the amount of flow restriction between the storage material in the fuel vapor canister from the first amount to a second, higher amount while maintaining the duty-cycle of the pump to continue providing the second amount of vacuum to the fuel vapor canister. |
