Methods and systems are provided for the integration of a fuel level sensor and a fuel pressure sensor in a fuel tank within a fuel system. In one example, an integrated fuel pressure and fuel level sensor for a fuel tank may include a float arm of the fuel sensor coupled to a floating body and a pressure sensor (e.g., a fuel tank pressure transducer) coupled to the floating body, the integrated fuel pressure and fuel level sensor adapted to simultaneously measure fuel level and fuel vapor pressure of the fuel tank.

A two-stage changeover valve is provided in a vaporized fuel passage connected between a fuel tank and a canister. A valve member is movably accommodated in a fluid passage formed in a valve housing. A valve seat is formed at an inner peripheral wall of the valve housing, so that the valve member is operatively seated on the valve seat. A restricted communication hole is formed in the valve member, so that an upstream side and a downstream side of the valve member are communicated with each other, even when the valve member is seated on the valve seat. The restricted communication hole is formed in a Laval-nozzle shape, so that vaporized fuel passing through the restricted communication hole is accelerated. As a result, a process for depressurizing inner pressure of the vaporized fuel in the fuel tank can be carried out in a shorter time.

A fuel tank system constructed in accordance to one example of the present disclosure includes a fuel tank and an evaporative emissions control system. The evaporative emissions control system is configured to recapture and recycle emitted fuel vapor. The evaporative emissions control system includes a liquid trap, a first device, a second device, a control module and a G-sensor. The first device is configured to selectively open and close a first vent. The second device is configured to selectively open and close a second vent. The control module regulates operation of the first and second devices to provide over-pressure and vacuum relief for the fuel tank. The G-sensor provides a signal to the control module based on a measured acceleration.

Methods and systems are provided for conducting a diagnostic routine of the fuel vapor system using pressure generated by raising or lowering a vehicle body element such as a hood or a trunk. In one example, by utilizing lift gate cylinders coupled to the hood or trunk, during raising a hood or trunk, the fuel vapor system may be evacuated and during lowering the hood or trunk, the fuel vapor system may be pressurized. A change in vacuum or higher pressure in the fuel vapor system may be monitored over a time period to detect any undesirable evaporative emissions from the fuel vapor system.

Methods and systems are provided for generating vacuum via an ejector arranged in a compressor recirculation flow path and an aspirator arranged in a throttle bypass path, where a suction port of the ejector is coupled with a canister purge valve having two outlet ports. In one example, the canister purge valve may include only a single flow restriction, the flow restriction arranged in a path coupling a fuel vapor purge system with the intake manifold when a solenoid of canister purge valve is open, such that a path coupling the fuel vapor purge system with the suction port of the ejector does not include any flow restrictions upstream of the suction port.

Methods and systems are provided for a fuel system. In one example, a method may include cleaning an orifice of an ELCM. The cleaning includes adjusting a position of a valve in a passage to fluidly couple a reference orifice of the ELCM to an intake manifold.

A turbocompressor boost purge ejector tee includes a first passage formed into a housing along a common axis from a first direction, the first passage including an outlet in communication with an inlet area of the turbocompressor. A second passage is formed into the housing along the common axis from a second direction and includes a boost air inlet in communication with a turbocompressor high pressure internal outlet area and fluidly coupled to the first passage. The first and second passages of the housing defining a first flow path from the internal outlet area to the inlet area. An inlet port is associated with the housing and intersects the first passage, the housing defining a second flow path from the inlet port to the outlet, and the second flow path intersecting the first flow path upstream of the outlet. A nozzle is positioned in the second passage.

An evaporative emissions (EVAP) control system for a vehicle includes a purge pump configured to pump fuel vapor trapped in a vapor canister to an engine of the vehicle via a vapor line when engine vacuum is less than an appropriate level for delivering fuel vapor to the engine, the fuel vapor resulting from evaporation of a liquid fuel stored in a fuel tank of the engine. The EVAP control 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. The EVAP control system also includes a controller configured to, based on the measured amount of HC, control at least one of the purge pump and a purge valve to deliver a desired amount of fuel vapor to the engine.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.

A leak hole determination device in an evaporated fuel processing system. The leak hole determination device includes: a first pressure detector for detecting a first pressure in a fuel tank; a second pressure detector for detecting a second pressure in a canister; and a leak hole determiner for determining whether a leak hole is present. The leak hole determiner determines, after a limit pressure timing subsequent to a depressurization operation for depressurizing an inside of the system, whether a leak hole is present by using a difference between a change speed of a first pressure detected by the first pressure detector and a change speed of a second pressure detected by the second pressure detector.