An evaporative emissions (EVAP) control system for a vehicle includes a purge pump configured to pump fuel vapor to a direct injection (DI) engine of the vehicle via a vapor line and a purge valve and a hydrocarbon (HC) sensor disposed configured to measure an amount of HC in the fuel vapor. The system also includes a controller configured to detect an HC vapor supply condition indicative of an operating condition of the Di engine where engine vacuum is less than an appropriate level for delivering the fuel vapor to the DI engine via the vapor line; and in response to detecting the HC vapor supply condition, controlling at least one of the purge pump and the purge valve, based on the measured amount of HC, to deliver a desired amount of fuel vapor to the DI engine to decrease particulate matter (PM) produced by the DI engine.

An evaporative emissions (EVAP) control system for a vehicle includes a purge pump configured to pump fuel vapor to an engine of the vehicle via a vapor line and a purge valve. The system includes a hydrocarbon (HC) sensor disposed in the vapor line and configured to measure an amount of HC in the fuel vapor pumped by the purge pump to the engine via the vapor line. A controller is configured to: detect an imminent cold start of the engine and, in response to the detecting, perform the cold start of the engine by controlling at least one of the purge pump and the purge valve, based on the measured amount of HC, to deliver a desired amount of fuel vapor to the engine, which decreases HC emissions by the engine.

A diagnostic method and system includes a control valve configured to control an amount of air drawn into an evaporative emissions (EVAP) system through an air filter and a vapor canister, and a pressure sensor configured to measure pressure in the EVAP system. The system also includes a controller configured to detect an engine idle-to-off transition and, in response to detecting the engine idle-to-off transition: receive a first pressure from the pressure sensor, fully open a purge valve connected between the vapor canister and an intake port of an engine, fully close the control valve, monitor one or more second pressures received from the pressure sensor, and detect a malfunction of the EVAP system based on the first pressure, at least one of the one or more second pressures, and a diagnostic threshold.

A fuel system comprising a fuel tank, a mixing volume configured to mix fuel vapor and air, the mixing volume comprising an outlet configured to be fluidly coupled to an engine, and a fuel vapor line configured to fluidly couple the fuel tank to the mixing volume.

A method for diagnosing operation of a valve to purge a canister of an internal combustion engine, the method, carried out during a purge, including: a) detecting, at an instant to, that the purge valve is open; b) executing a forced closing of the valve at an instant t2; c) measuring a pressure P1m of the intake manifold and calculating a corresponding modelled pressure P1c, at an instant t1 between the instant t0 and the instant t2; d) measuring a pressure of the manifold P2m and calculating a corresponding modelled pressure P2c, at an instant t3 after the instant t2; e) calculating a deviation E1 between P1m and P1c and calculating a deviation E2 between P2m and P2c; f) calculating a criterion C=E1−E2; and g) diagnosing malfunction of the purge valve if the criterion C is lower than a predetermined threshold value Cs.

Methods and systems for diagnosing operational status of a carbon filled canister heater are described. The methods and systems may include activating an evaporative emissions system heater, a pump, and a canister purge valve to determine if long chain hydrocarbons are released from a carbon filled canister. Release of long chain hydrocarbons from the carbon filled canister may be indicative of desired operation of a carbon filled canister heater.

Methods and systems are provided for controlling a vehicle engine to reduce engine knock and increase fuel efficiency by reducing hydrocarbon breakthrough. In one example, a method may include adjusting a compression ratio of a variable compression engine in response to hydrocarbon breakthrough above a threshold from a fuel vapor canister of an evaporative emissions system.

A method for controlling a control valve, the control valve controlling a volume flow of a fluid along a line, the method including at least the following steps: (a) performing a closing operation of the control valve; (b) measuring a pressure profile upstream of the control valve; and (c) determining a density of the fluid.

Methods and systems for controlling and reducing current consumption of a vapor blocking valve are disclosed. In one example, current supplied to the vapor blocking valve is adjusted proportionately to fuel tank pressure to compensate for fuel tank pressure acting on the vapor blocking valve. Vapor blocking valve current is adjusted to reduce current consumption.

Embodiments for controlling fuel vapors are disclosed. In one example, a method comprises during a purge of a fuel vapor canister, adjusting a heater of the fuel vapor canister based on a rate of a purge flow exiting the fuel vapor canister and a concentration of hydrocarbons released from the fuel vapor canister. In this way, a fuel vapor canister purge efficiency may be increased.