A method for venting the tank of a vehicle, a device for venting the tank of a vehicle, as well as a vehicle are provided. In this context, the vehicle in which the method is employed has an internal combustion engine that can be operated with a fuel, an air supply system, an exhaust gas system comprising at least an exhaust gas turbocharger, a fuel tank that is designed to supply the internal combustion engine with fuel, and a fuel vapor sorption system. It is provided that, in the method or by means of the device, a drive flow in the air supply system is regulated as a function of an altitude reserve of the exhaust gas turbocharger and as a function of an engine load point, so that the flushing air volume flow of the tank venting system that ensues is determined and can be supplied as a function of an altitude rotational speed of the exhaust gas turbocharger and as a function of the engine load point.

Disclosed is a method for diagnosing sealing in a fuel vapor recirculation system for an engine of a motor vehicle. An electronic module is integrated into the engine control unit that is woken up and placed on standby periodically while the engine is off, at the start and end of time intervals in order to perform a respective leak diagnosis, the fuel vapor temperature Tsys being estimated as a function of a time t ending at the start of each interval and starting when the engine is switched off according to the following equation, in which Tamb is the ambient temperature measured, Tsys0 is the fuel vapor temperature when the vehicle is switched off, and tsys is a system response time:
Tsys(t)=Tamb+(Tsys0−Tamb)e.sup.−t/tsys.

Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine is in a fuel cut-out mode and fuel vapors are being released to the engine via a fuel vapor storage canister.

A dual purge ejector and a dual purge system using the same are provided. A first end of a main body is fully open and an ejecting end of a nozzle is located proximate to the opening hole. Therefore, even if the ejector is disconnected from an adapter, negative pressure is not formed in a main body, to prevent discharge of fuel evaporation gas into the atmosphere and a failure of the dual purge system may be reliably diagnosed.

A first arrival flow rate that is a flow rate of evaporative fuel gas that has arrived in a throttle downstream portion located downstream of a throttle valve in an intake pipe via a second purge passage after passing through a purge control valve is estimated based on a valve passage flow rate that is a flow rate of evaporative fuel gas that has passed through the purge control valve, and a first response delay in the flow of evaporative fuel gas through a route extending from the purge control valve to the throttle downstream portion via the second purge passage.

When a predetermined condition is satisfied, a flow rate ratio of a first passage flow rate to a second passage flow rate is estimated based on a throttle post pressure being a pressure on a downstream side of an intake pipe with respect to a throttle valve and an ejector pressure being a pressure of a suction port of an ejector. The first passage flow rate is a flow rate of an evaporated fuel gas flowing in a first purge passage. The second passage flow rate is a flow rate of the evaporated fuel gas flowing in a second purge passage. The first passage flow rate and the second passage flow rate are estimated based on the flow rate ratio and a valve passing flow rate being a flow rate of the evaporated fuel gas that passes through a purge control value.

An evaporated fuel processing device that includes a fuel tank; a vapor passage through which evaporated fuel generated from a fuel in the fuel tank flows; a closing valve configured to open and close the vapor passage; a concentration sensor configured to detect a concentration of the evaporated fuel in the vapor passage downstream of the closing valve; and a controller. When the closing valve moves toward an open side in the closed state, the controller may specify a valve-opening-start position of the closing valve based on a concentration detected by the concentration sensor, wherein the valve-opening-start position is a position where the closing valve transitions from the closed state to the opened state.

An evaporated fuel treatment apparatus is provided with a purge pump and a purge valve and an electronic control unit (ECU) for controlling the purge pump and the purge valve. The ECU, when performing purging, opens the purge valve to control the purge pump at the rated rotational speed, and when stopping purging, closes the purge valve to control the purge pump at a zero rotational speed. When starting purging, the ECU gradually controls the purge pump from a rotational speed lower than the rated rotational speed toward the rated rotational speed before opening the purge valve which is in the closed state, and opens the purge valve when the purge pump reaches a first threshold rotational speed lower than the rated rotational speed during the performing the control.

An evaporated fuel processing device is installed to a vehicle having an internal combustion engine and a fuel tank and is configured to process evaporated fuel generated through evaporation of fuel in the fuel tank. A control device of the evaporated fuel processing device is configured to adjust an opening degree of a sealing valve based on a pressure of vapor-phase gas sensed with a pressure sensor and a concentration of evaporated fuel in the vapor-phase gas sensed with a concentration sensor and thereby adjust a supply amount of the evaporated fuel supplied to an air intake pipe at a time of executing a purge operation, in which the vapor-phase gas is purged from the fuel tank to the air intake pipe of the internal combustion engine.

A control device transmits an opening degree command amount to an actuator to command an opening degree of a sealing valve. The control device sets a pressure difference between a tank-side pressure and a canister-side pressure to a specified value or more. The control device causes a pressure variable device to change the canister-side pressure to form a state in which the pressure difference becomes equal to or higher than a specified value while the sealing valve is closed. The control device learns a valve opening start amount based on the opening degree command amount when the tank-side pressure changes in response to the opening degree command amount that gradually increases from zero. The control device determines the opening degree command amount based on the valve opening start amount, which has been learned.