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 diagnosing a heating element coupled to a canister of an evaporative emissions control (EVAP) system. In one example, a method (or system) may include evacuating the canister at different temperature conditions, and diagnosing the heating element based on the different times taken to evacuate the canister at the different temperature conditions.

A fuel tank system includes a fuel storage unit, a processing unit, and a control unit. The control unit performs a first failure diagnosis of diagnosing a failure of the fuel storage unit in a state where the sealing valve is closed. When the control unit diagnoses that the fuel storage unit is normal, the control unit performs a second failure diagnosis of diagnosing a failure of a purge valve and a bypass valve by causing a pressure generation unit to generate pressure in a state where the sealing valve is closed. When there is a possibility that the purge valve and the bypass valve are in closed-sticking, the control unit performs a third failure diagnosis of specifying a failure in any one of closed-sticking of the purge valve and closed-sticking of the bypass valve by opening the sealing valve.

A rotary vane pump includes a housing that includes first and second plates respectively secured to first and second opposing sides of an intermediate plate. The intermediate plate includes a bore and inlet and outlet ports. The first and second sides respectively have first and second passages that are respectively in fluid communication with the inlet and outlet ports. The first and second passages are in fluid communication with the bore. The intermediate plate is reversible with respect to the first and second plates. A rotor is arranged in the bore. The rotor supports slidable vanes that are configured to pump fluid between the inlet and outlet ports.

A vehicle includes a fuel tank, a canister, a first valve, a second valve, a heater, and a controller. The fuel tank is configured to store fuel. The canister is in fluid communication with the fuel tank and is configured to receive and store evaporated fuel from the fuel tank. The first valve is disposed between the fuel tank and the canister. The second valve is disposed between the canister and ambient surroundings. The heater is disposed within the canister. The controller is programmed to, periodically initiate diagnostic tests that are configured to determine if the heater is operating properly, if the heater is unable to turn off, or if the heater is unable to turn on.

A leakage detector includes a pressure sensor for detecting the pressure in a detecting target area of the fuel vapor treatment system and a controller. The controller measures the pressure in the detecting target area at a certain point in time. The controller then determines whether the measured pressure satisfies a condition for leakage detection by a vapor pressure device. When the controller determines that the condition is satisfied, the controller selects the vapor pressure device. When the controller determines that the condition is not satisfied, the controller predicts the change in vapor pressure at a subsequent temperature based on a saturated vapor pressure characteristic of the fuel. If it is determined the pressure in the detecting target will satisfy a predetermined condition, the controller selects a pressure application device. If it is determined that the predetermined condition will be satisfied, the controller selects the vapor pressure device.

A vehicle includes at least one of an electric vent valve configured to open and close an outside-air-introduction passage of a canister or an electric suction pump configured. to suck gas in a gas passage through which the gas flows. The canister and at least one of the vent valve or the suction pump are disposed such that at least one of a virtual-left-right-center plane that includes a center in a left-right direction and is perpendicular to the left-right direction, a virtual-front-rear-center plane that includes a center in a front-rear direction and is perpendicular to the front-rear direction, or a virtual-up-down-center plane that includes a center in an up-down direction and is perpendicular to the up-down direction is located between a gravity center of the canister and at least one of a gravity center of the vent valve or a gravity center of the suction pump.

A vapor canister for a vehicle evaporative emissions control system comprises a canister housing defining an internal volume for receiving therein one or more volumes of adsorbent; a fuel vapor inlet port for connecting the canister to a fuel tank; a vent port for intake of fresh air into the canister; a purge port for withdrawing fuel vapors from the canister; and a pump integrated with the canister housing. The integrated pump is actuated to provide an overpressure or underpressure in the canister. The integrated pump can be used for various operating modes, such as e.g. canister purging, leak detection diagnostic, refueling or engine shut down.

An evaporated gas leak diagnosis method using an active purge pump is provided to detect a leak of the evaporated gas from a canister in a fuel system. The method includes diagnosing a failure of an active purge pump based on a signal generated by a pressure sensor installed on a vent line that extends from the canister to the atmosphere. The active purge pump is mounted on a purge line for connecting the canister with an intake pipe.

A failure diagnosis method and a failure diagnosis system of a dual purge system may determine whether a closed stuck failure or an opened stuck failure occurs in a line forming a dual purge system by measuring a pressure in a negative pressure formation device and comparing the corresponding pressure with a predetermined reference value when a purge valve of the dual purge system is in an opened or closed state, and may determine whether the failure occurs in components related to a secondary purge line in the dual purge system in which it is difficult to determine whether the failure occurs in a conventional failure diagnosis method of a single purge system in a simple method.