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.

The present description provides low DBL bleed emission performance properties that allows the design of evaporative fuel emission control systems that are simpler and more compact than those possible by prior art by inclusion of a vent-side volume comprising a parallel passage adsorbent such as a carbon honeycomb with narrow channel width and low cell pitch.

A cylindrical column-shaped honeycomb adsorbent has a plurality of cell passages extending along an axial direction of the honeycomb adsorbent. The plurality of cell passages are configured so that a pitch of adjacent cell passages is within a range of 1.5 mm˜1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm˜0.60 mm. With this configuration, the honeycomb adsorbent exhibits BWC (Butane Working Capacity) of 6.5 g/dL or greater. By mixing fibrous meltable core melting away during baking, the honeycomb adsorbent has macropores configured to have a volume of 0.15 mL/g˜0.35 mL/g with respect to an overall weight of the honeycomb adsorbent and metal oxide particles having a proportion of weight of 150˜250% with respect to the activated carbon.

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.

Sorbent material sheets provide for enhanced performance in vapor adsorbing applications over conventional canisters and other emissions control equipment. The sorbent material sheets can be formed as part of a small, lightweight canister, or can be integrated into a fuel tank. The sorbent material sheets can also be used as part of an onboard refueling vapor recovery system to control volatile organic compound emissions from fuel tanks of gasoline vehicles, such as automobiles.

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.