Abstract: A purge valve and a fuel vapor management system for use with an engine emission control system are disclosed. The purge valve may include a first inlet for receiving a first flow of air from an air cleaner, a second inlet for receiving a second flow of purge vapors from an evaporative canister, and an outlet directing a controlled mixture of the first and second flows to an engine, upstream of an intake throttle. Relative amounts of the first flow and second flow may be selectively controlled by varying a position of the valve.

Abstract: Methods and systems are provided for purging a multi-port canister into an engine intake. Air is circulated through the canister and a resulting purge air is directed to an intake passage upstream of a throttle in engine configured with a throttle body. An amount of fresh intake air received at the intake passage is corresponding decreased.

Abstract: Methods and systems are provided for performing a vehicle-off fuel system leak test. A vehicle controller may be woken up after a vehicle has been in a key-off condition for a sufficient amount of time to monitor a fuel tank for pressure and temperature stabilization. If the pressure and temperature of the fuel tank is stable, a fuel pump may be operated to raise a fuel tank vapor pressure, and fuel system leaks are identified based on a rate of pressure decay from the fuel tank.

Abstract: A method for operating a fuel system is disclosed. The method includes sequentially purging fuel vapors from each of a plurality of regions of a canister. Purging a region includes opening an air inlet valve associated with that region and maintaining air inlet valves associated with each other region closed to direct fuel vapors to at least one purge outlet.

Abstract: Various methods and systems are provided for reducing pressure in a fuel tank of a fuel system of an engine. In one example, cooling fluid is routed from an air conditioner of a cooling system to a vapor cooler disposed in a vapor space of the fuel tank such that fuel vapor in the fuel tank may be condensed and routed to a fuel pump for delivery to the engine, thereby reducing a fuel tank pressure.

Abstract: A purge control valve control system is provided for an internal combustion engine system, comprising: a voltage source having a positive potential and a negative potential; a purge control valve having a solenoid, such solenoid comprising an electrically inductive element, such inductive element having a first terminal coupled to the positive potential of the voltage source; a diode having an anode and a cathode. The control unit includes a transistor having: a control electrode fed by a train of pulses; a first electrode coupled to the negative potential of the voltage source; and a second electrode coupled to a second terminal of the inductive element and to the diode.