A method for operating a vehicle system is provided. The method includes monitoring a change in a temperature of the fuel vapor canister coupled to a fuel tank via a canister temperature sensor and adjusting operation of a fuel tank isolation valve based on the change in temperature of the fuel vapor canister.

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.

A system according to the present disclosure includes a valve control module, a purge fraction module, and a diagnostic module. The valve control module opens a purge valve in an evaporative emissions system to allow purge vapor to flow to an intake system of an engine. The purge fraction module determines first and second fractions of purge vapor delivered to the engine relative to a total amount of air and purge vapor delivered to the engine based on first and second inputs, respectively. The first input is from a hydrocarbon sensor disposed in the evaporative emissions system of the engine. The second input is from an oxygen sensor disposed in an exhaust system of the engine. The diagnostic module selectively diagnoses a fault in at least one of the evaporative emissions system and the hydrocarbon sensor based on the first and second purge fractions when the purge valve is open.

Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

In a vaporized fuel processing apparatus in which fuel vapor within a fuel tank is adsorbed by a canister, the adsorbed vaporized fuel is drawn to an engine, a closing valve is provided connecting the fuel tank and the canister for controlling communication between the fuel tank and the canister, and a purge valve is provided connecting the canister and the engine for controlling communication between the canister and the engine. The vaporized fuel processing apparatus includes an internal pressure sensor configured to detect a pressure of a space within the fuel tank as an internal pressure, and a closing valve control means configured to open the closing valve for supplying an atmospheric pressure to the fuel tank via the canister when the sensor detects that the internal pressure of the fuel tank is negative, while the purge valve is closed. Therefore, the air/fuel ratio is prevented from being disturbed.

An evaporated fuel processing device that includes a pressurizing pump configured to pressurize gas in the vapor passage downstream of the closing valve toward the closing valve; a first pressure sensor configured to detect a pressure in the fuel tank directly or indirectly, and/or a second pressure sensor configured to detect a pressure in the vapor passage downstream of the closing valve directly or indirectly. When the closing valve moves toward an open side in the closed state with the pressurizing pump pressurizing the gas in the vapor passage downstream of the closing valve toward the closing valve, the controller may specify a valve-opening-start position based on the pressure detected by the first pressure sensor and/or the pressure detected by the second pressure sensor, wherein the valve-opening-start position is a position where the closing valve transitions from the closed state to the opened state.

A vaporized fuel processing device includes a fuel tank storing fuel used for an internal combustion engine, a pressurizing portion performing a pressurizing process to increase an inner pressure of the fuel tank by supplying gas from outside to inside the fuel tank, and a controller controlling an operation of the pressurizing portion. The controller controls the pressurizing portion to perform the pressurizing process and to keep the inner pressure of the fuel tank at or above a predetermined pressure value at which vaporized fuel is prevented from flowing out of the fuel tank, except for a time of fueling of the fuel tank.

Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

An engine system includes: a first throttle valve; a turbocharger compressor disposed downstream of the first throttle valve; a charge air cooler disposed downstream of the turbocharger compressor; a second throttle valve located downstream of the turbocharger compressor; a purge inlet located downstream of the first throttle valve and configured to introduce fuel vapor from a fuel tank into intake air; and an engine control module configured to: maintain the first throttle valve in a fully open position; and selectively close the first throttle valve relative to the fully open position in response to receipt of a request to at least one of: purge fuel vapor from the fuel tank; and at least one of decrease and prevent icing of the charge air cooler.

A purge device includes a canister; a purge passage configured to extend from the canister and be connected to an upstream side of a compressor of a supercharger in an intake passage; a supply unit configured to supply purge gas to the upstream side of the compressor in the intake passage during supercharging; a throttle configured to be provided in a portion of the intake passage connected with the purge passage and limit an inflow of gas from the purge passage; a sensor configured to detect internal pressure downstream of the supply unit in the purge passage; and a control device configured to determine that a passage end of the purge passage deviates from the intake passage, in a case where a detection value obtained by the sensor during the operation of the supply unit is lower than a predetermined pressure.