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.

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.

An evaporative fuel processing device for determining a leak of an evaporation piping system also determined pump abnormality by including a pump, a pressure sensor and an abnormality determiner, i.e., by pressuring/de-pressuring the system to a positive/negative value against an atmospheric pressure for leak determination, by detecting a pressure of the system, and by determining a leak hole in a normal leak determination mode based on an absolute value of the detected pressure reaching or not reaching a target value after pump operation and based on an assumption that the pump is normal. Specifically, after lapse of a determination time from a pump stop, the absolute value equal to or less than a normal leak determination threshold value is determined that a leak hole is present in the system. Further, the absolute value not reaching the target value even after pump operation triggers a pump abnormality determination mode.

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.

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.

A method for monitoring for a rupture in a storage element of a fuel tank system having a fuel tank includes: detecting, by a mass flow sensor, thermal conductivity of an unmoved air mass in a first line of the fuel tank system; and identifying a rupture in the storage element if the detecting by the mass flow sensor detects a change in the thermal conductivity of the unmoved air mass in the first line when a second valve is in a closed state and/or when an air pump is at a standstill.

An evaporated fuel processing device utilizing a flow rate control valve as a valve positioned in a passage connecting a fuel tank with a canister. The device includes: a valve opening means for opening the flow rate control valve at a constant speed; an internal pressure sensor; a valve opening start position detecting means for acquiring a second derivative value of the internal pressure after a valve opening motion of the flow rate control valve has started and for detecting a valve opening start position of the flow rate control valve based on the second derivative value; a learning means for storing the valve opening start position; and a valve opening speed change means for changing a valve opening speed of the valve opening means based on a variation speed of the internal pressure before the valve opening motion of the flow rate control valve has started.

A vapor purge system for an engine, includes a purge valve having a housing including an input port in communication with a purge canister and including an output port in communication with an intake system component defining a first bore portion receiving the output port with a first seal member disposed therebetween. The intake system component includes a second bore portion receiving a housing portion of the purge valve with a second seal member disposed therebetween. The first and second seal members are spaced such that when the housing is pulled away from the intake system component and the first seal member is out of engagement between the first bore and the output port, the second seal member can remain in engagement so that a diagnostic module can diagnose detachment of the purge valve from the intake system before any hydrocarbon vapor can be released into the atmosphere.

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.

The present invention relates to a device for inspecting a canister for a vehicle, the device including: an inspection unit fixing a canister and inspecting airtightness of the canister using pressure of air supplied from an external supply source; a control unit controlling the pressure of the air and showing inspection process and result by the canister; and an alarm unit providing least any one of a voice and light warning in cooperation with the control unit in an inspection process when a defect of canister is detected.