A method for operating an internal combustion engine. The method includes: operating the internal combustion engine including a lambda regulation, which sets a fuel quantity to be supplied in accordance with a predefined setpoint lambda value, at preset times, carrying out a filter cleaning operation for a fuel tank ventilation, as a function of the presence of a release condition of the internal combustion engine, carrying out an adaptation of the lambda regulation by adapting at least one adaptation parameter as a function of operating variables of the internal combustion engine, at active filter cleaning operation and upon the presence of the release condition, operating variables which are required to carry out the adaptation of the lambda regulation being recorded, at deactivated filter cleaning operation and presence of the release condition, the adaptation of the lambda regulation being carried out as a function of the recorded operating variables.

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.

A fuel tank vent valve includes a venting apparatus for regulating discharge of fuel vapor from a fuel tank and admission of outside air into a fuel tank. The vent valve is used to regulate pressure in a fuel tank.

Methods and systems are provided for indicating whether a canister purge valve in a vehicle evaporative emissions control system is degraded. In one example, an air intake system hydrocarbon (AIS HC) trap temperature may be monitored during a refueling event, and responsive to an indication that the AIS HC trap temperature change is greater than a predetermined threshold, it may be indicated that the canister purge valve is degraded. In this way, diagnosis of whether a vehicle canister purge valve is degraded may be indicated without the use of engine manifold vacuum, and may be advantageous for vehicles configured to operate for significant amounts of time without engine operation, or without intake manifold vacuum.

A hybrid vehicle includes a canister that adsorbs evaporative fuel generated in the fuel tank for an internal combustion engine. The hybrid vehicle can drive a drive wheel even when the internal combustion engine is stopped. When the internal combustion engine of the hybrid vehicle is stopped and a prescribed set of conditions is satisfied, the internal combustion engine is rotated by the generator. When the internal combustion engine of the hybrid vehicle is rotated by the generator, the evaporative fuel adsorbed in the canister is supplied to the upstream side of an upstream side exhaust catalytic converter device. In the hybrid vehicle, the introduced evaporative fuel as reducing agent is adsorbed in the upstream side exhaust catalytic converter device and a downstream side exhaust catalytic converter device.

Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.

Methods and systems are provided for reverse purging of a fuel vapor canister of an engine. In one example, a method may include heating a fuel vapor canister, sealing a fuel tank in order to generate a vacuum in the fuel tank, and in response to the pressure in the fuel tank reaching a target vacuum, initiating reverse purging of the fuel vapor canister.

There is provided a valve device including: a housing in which a valve chamber is provided on a lower side and a ventilation chamber is provided on an upper side via a partition wall, the partition wall being formed with a valve hole; a float valve; and a pressure adjusting valve. An accommodation portion is provided in a protruding manner from a surface of the partition wall. An accommodating space configured to accommodate the pressure adjusting valve is formed on an inner side of the accommodation portion, and an outer space is formed on an outer side of the accommodating space. The accommodation portion is formed with an opening through which the accommodating space and the outer space communicate with each other.

A vehicle includes an engine, a fuel tank, a primary canister, a buffer canister, a purge valve, a check valve, and a controller. The fuel tank is configured to store fuel. The primary canister is configured to receive and store evaporated fuel from the fuel tank. The buffer canister is configured to receive and store the evaporated fuel from the fuel tank. The buffer canister is disposed between the primary canister and the engine. The purge valve is disposed between the buffer canister and the engine. The purge valve is configured to direct the evaporated fuel from the primary and buffer canisters to the engine when open. The check valve is disposed between the primary and buffer canisters and is configured to restrict backflow of the evaporated fuel from the buffer canister toward the primary canister. The controller is programmed to diagnose the operability of the check valve.

A dual purge system for a vehicle includes an ejector including a drive inlet section connected to a first end of a main body section, a suction inlet section connected to a first side of the main body section, an outlet section coupled to an intake passage section, a nozzle section, and a diffuser, wherein the diffuser communicates with internal passages of the main body section and the outlet section and has a larger passage cross-sectional area than a channel cross-sectional area of an outlet of the nozzle section, wherein a driving fluid flows through the drive inlet section, in response to a negative pressure being produced in the main body section by the driving fluid, the suction inlet section suctions a fuel evaporation gas from a canister, and the outlet section discharges the driving fluid and the fuel evaporation gas.