Abstract: A fuel system, a vehicle, and a method of controlling an evaporative emissions system for the vehicle are provided. The fuel system has a fuel tank having a fuel fill port with a closure member. An evaporative emissions canister has a first port fluidly coupled to the fuel tank to receive vapor therefrom and a second port, with the canister positioned between an air intake for an engine and a vent to atmosphere. A filter or a second canister is supported by a bracket for movement between first and second positions, with the filter fluidly coupling the second port of the canister to the vent in the first position, and the filter spaced apart from and decoupled from the second port of the canister in the second position. The second port of the canister is in direct fluid communication with atmosphere when the filter is in the second position.

Abstract: A fuel system, a vehicle, and a method of controlling an evaporative emissions system for the vehicle are provided. The fuel system has a fuel tank having a fuel fill port with a closure member. An evaporative emissions canister has a first port fluidly coupled to the fuel tank to receive vapor therefrom and a second port, with the canister positioned between an air intake for an engine and a vent to atmosphere. A filter or a second canister is supported by a bracket for movement between first and second positions, with the filter fluidly coupling the second port of the canister to the vent in the first position, and the filter spaced apart from and decoupled from the second port of the canister in the second position. The second port of the canister is in direct fluid communication with atmosphere when the filter is in the second position.

Abstract: Methods and systems are provided for reducing a potential for release of undesired evaporative emissions to atmosphere for vehicles that rely primarily on an electric-only mode of operation for vehicle propulsion. In one example, a method may include in response to a vehicle-on request via a driver of a vehicle, maintaining off a fuel pump that supplies a fuel to a set of port fuel injectors, and re-pressurizing the set of port fuel injectors via operation of the fuel pump based on a predicted engine-start request during a drive cycle following the vehicle-on request. In this way, escape of fuel from pressurized port fuel injectors may be reduced or avoided during engine-off conditions, which may reduce opportunity for release of undesired evaporative emissions to atmosphere.

Abstract: Methods and systems are provided for reducing a potential for release of undesired evaporative emissions to atmosphere for vehicles that rely primarily on an electric-only mode of operation for vehicle propulsion. In one example, a method may include in response to a vehicle-on request via a driver of a vehicle, maintaining off a fuel pump that supplies a fuel to a set of port fuel injectors, and re-pressurizing the set of port fuel injectors via operation of the fuel pump based on a predicted engine-start request during a drive cycle following the vehicle-on request. In this way, escape of fuel from pressurized port fuel injectors may be reduced or avoided during engine-off conditions, which may reduce opportunity for release of undesired evaporative emissions to atmosphere.

Abstract: Methods and systems are provided for controlling a vehicle fuel pump at a fuel shut-off event based at least in part on whether combustion stability issues, or potential stall conditions, are indicated in a drive cycle prior to the fuel shut-off event. In one example, a method may include maintaining power to the fuel pump responsive to the potential stall condition being indicated, and independent of an indicated pressure in a fuel rail configured to receive pressurized fuel from the fuel pump, and where the fuel shut-off event includes a deceleration fuel shut-off event or an idle stop event. In this way, fuel may be kept flowing across the fuel pump during fuel shut-off events, responsive to indications of combustion stability issues, such that fuel pump cavitation and other engine and fuel pump-related complications may be avoided.

Abstract: Methods and systems are provided for controlling a vehicle fuel pump at a fuel shut-off event based at least in part on whether combustion stability issues, or potential stall conditions, are indicated in a drive cycle prior to the fuel shut-off event. In one example, a method may include maintaining power to the fuel pump responsive to the potential stall condition being indicated, and independent of an indicated pressure in a fuel rail configured to receive pressurized fuel from the fuel pump, and where the fuel shut-off event includes a deceleration fuel shut-off event or an idle stop event. In this way, fuel may be kept flowing across the fuel pump during fuel shut-off events, responsive to indications of combustion stability issues, such that fuel pump cavitation and other engine and fuel pump-related complications may be avoided.

Abstract: Systems and methods for operating an engine with a fuel vapor recovery system are disclosed. In one example approach, a method comprises, during a diurnal condition, providing a first amount of venting to a fuel vapor canister, and during a purge condition, providing a second amount of venting to the fuel vapor canister, where the second amount is greater than the first amount.

Abstract: A method for improving purging of fuel vapors from a fuel vapor storage canister to an engine is presented. In one example, the method adjusts engine operation to provide sonic flow between a canister and the engine. In this way, it may be possible to lower an amount of fuel vapors stored in a canister while the engine continues to operate efficiently.

Abstract: Methods and systems are provided for controlling a fuel system in a hybrid vehicle. Before canister purging is stopped by closing a purge valve, a canister vent valve is closed to hold fuel tank vacuum. Then, during a subsequent canister purge, the purge valve is opened before opening the vent valve, allowing canister purge to initiate under fuel tank vacuum conditions.

Abstract: Systems and methods for operating an engine with a fuel vapor recovery system are disclosed. In one example approach, a method comprises, during a diurnal condition, providing a first amount of venting to a fuel vapor canister, and during a purge condition, providing a second amount of venting to the fuel vapor canister, where the second amount is greater than the first amount.

Abstract: Methods and systems are provided for controlling a fuel system in a hybrid vehicle. Before canister purging is stopped by closing a purge valve, a canister vent valve is closed to hold fuel tank vacuum. Then, during a subsequent canister purge, the purge valve is opened before opening the vent valve, allowing canister purge to initiate under fuel tank vacuum conditions.

Abstract: A method for improving purging of fuel vapors from a fuel vapor storage canister to an engine is presented. In one example, the method adjusts engine operation to provide sonic flow between a canister and the engine. In this way, it may be possible to lower an amount of fuel vapors stored in a canister while the engine continues to operate efficiently.

Abstract: The present disclosure relates to a computer-implemented method of controlling an engine fuel pump in a hybrid-electric vehicle. The method includes: cycling a vehicle powertrain between an electric mode, where an engine is commanded off, and a mechanical mode, where the engine is commanded on; depowering an engine fuel pump when the engine is commanded off; and determining if the engine is operating in a fuel shut-off mode.

Abstract: A method for controlling an automotive canister purge valve in fluid communication with an evaporative canister includes selecting a purge flow rate of increase for the purge valve based on a hydrocarbon concentration in a fluid stream exiting the evaporative canister, and operating the purge valve based on the selected rate.

Abstract: A method for controlling an automotive canister purge valve in fluid communication with an evaporative canister includes selecting a purge flow rate of increase for the purge valve based on a hydrocarbon concentration in a fluid stream exiting the evaporative canister, and operating the purge valve based on the selected rate.