Methods and systems are provided for a diagnostic of a pressure sensor. In one example, a method includes bypassing one or more vapor canisters and determining a condition of the pressure sensor based on feedback from a hydrocarbon sensor.

A vehicle includes a fuel tank, a primary canister, a secondary canister, a first valve, a second valve, a third valve, a heater, and a controller. The primary and secondary canisters are in fluid communication with the fuel tank and are configured to receive and store evaporated fuel from the fuel tank. The first valve is disposed between the fuel tank and the primary canister. The second valve is disposed between the secondary canister and ambient surroundings. The third valve is disposed between the primary canister and an engine. The heater is configured to heat the primary and secondary canisters. The controller is programmed to (i) activate the heater to heat the primary and secondary canisters and (ii) purge the evaporated fuel from the primary and secondary canisters after heating the primary and secondary canisters.

A carbon canister includes a main body with a chamber containing activated carbon, an end cover mounted to the main body, the end cover and the main body enclosing and forming a cavity, the end cover having a desorption port for connecting with and engine, a Venturi tube mounted in the cavity and including an inlet segment, and a throat and a back suction tube. An inner diameter of the throat is smaller than an inner diameter of the inlet segment. The inlet segment communicates with the activated carbon containing chamber, the throat communicates with the desorption port, the back suction tube connects to the throat, and the back suction tube extends to the bottom of the cavity. Thereby, a negative pressure is created, the fuel collected within the carbon canister is desorbed to the engine so that the fuel utilization is improved, and the exhaust emission is reduced.

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 control valve is disposed on a vapor control system which controls vapor. A case and caps hold a diaphragm. The case and the diaphragm define a primary chamber. The caps and the diaphragm define a secondary chamber. The secondary chamber communicates to an inlet passage via a through hole formed as an orifice. An inlet pipe is arranged so that the inlet passage and the secondary chamber are adjacent each other by being separated by an outer wall. By employing this arrangement, the through hole can be formed without increasing a vapor permeable surface area. Since the through hole is not formed on the diaphragm, a stable open-and-close characteristic can be provided. The through hole may be formed by using a molding die for forming the inlet passage. Thereby, it is possible to improve productivity.

A vaporized fuel treating device having a canister that is configured to adsorb vaporized fuel in a fuel tank and to feed the adsorbed vaporized fuel to an engine may include a pressure sensor that is configured to periodically detect an inner pressure of the fuel tank, and a pressure sensor failure determination device that is configured to determine that the pressure sensor has failed when a change of the inner pressure detected by the pressure sensor in a unit of time is not less than a predetermined pressure value that is greater than a maximum value of possible pressure changes within the fuel tank.

A pneumatically actuated vacuum pump is disclosed. The pneumatically actuated vacuum pump includes a body. The body defines at least two converging motive sections each having an outlet end, at least two diverging discharge sections each having an inlet end, and at least one Venturi gap. The Venturi gap is located between the outlet ends of the at least two converging motive sections and the inlet ends of the at least two diverging discharge sections.

Methods and systems are provided for indication of a degradation in an EVAP and/or fuel system. In one example, a method for indication of a presence or absence of a degradation in a refueling system may include vacuum pull-down and pressure bleed-up tests being carried out based on a state of submersion of a spud valve in liquid fuel in a fuel tank.

The concepts described herein provide for a system, apparatus and/or method for fuel vapor capture on-vehicle for evaporative emission control. This includes a device for capturing fuel vapor on-vehicle that includes a canister device having a first port that is fluidly coupled to a head space portion of a fuel tank. The canister device defines a chamber that is fluidly coupled in series between the first port and a second port. A first Metal Organic Framework (MOF) material is disposed in the chamber to adsorb fuel vapor constituents.

Venting of gaseous fuel during operation and after shutdown of an internal combustion engine increases emissions. A vent handling apparatus for a gaseous fuel system of an internal combustion engine comprises an accumulator for storing gaseous fuel; a first valve selectively enabling fluid communication between the accumulator and one of a gaseous fuel communication passage and a gaseous fuel storage vessel, the gaseous fuel communication passage delivering gaseous fuel to the internal combustion engine for combustion; and an apparatus for selectively returning the gaseous fuel from the accumulator to the internal combustion engine for combustion.