A method for improving accuracy of correction of fuel quantity at the time when a recirculation valve (RCV) is opened, may include a step of correcting injection amount of fuel based on consideration factors when the RCV is operated to be opened. The consideration factors include property values of a flow path of the RCV, the flow path being mounted to an intake pipe to connect between a front end of a compressor close to the atmosphere and a rear end of the compressor adjacent to combustion chambers, a first calculation value obtained by calculating amount of air to be introduced into the combustion chambers after circulating from the flow path of the RCV to the intake pipe, and a second calculation value obtained by calculating amount of hydrocarbon to be introduced into the flow path of the RCV by purging evaporative gas.

A flow control valve may include a housing including a fluid-flow channel, a valve seat including a valve hole and positioned in the fluid-flow channel, an electric motor disposed in the housing, and a valve body configured to be axially moved toward and away from the valve seat by the electric motor via a feed screw mechanism. The valve body includes a straight projecting portion. The projecting portion is configured to be positioned in the valve hole in an initial valve body lifting range in which a lift distance of the valve body relative to the valve seat is not greater than a predetermined lift distance.

Methods and systems are provided for reducing a possibility of hydrocarbon (HC) breakthrough during a diagnostic routine of an evaporative emissions control (EVAP) system. In one example, a method may include, during the diagnostic routine, switching a direction of air-flow through a fuel vapor canister via adjustments to a three-way valve in response to a higher than threshold a change in temperature within the canister.

A diagnostic device is configured to execute a first acquisition process of acquiring a remaining amount of evaporated fuel in a fuel tank when an ignition switch turns off, as an end remaining amount, a determination process of, after the first acquisition process, determining whether there is a blockage of a vapor passage by reducing a pressure in a vapor passage with a pressure reducing pump when the end remaining amount is smaller than a prescribed value while the ignition switch is off, a second acquisition process of, after the determination process, acquiring a remaining amount of liquid fuel in the fuel tank when the ignition switch turns on, as a start remaining amount, and an invalidation process of invalidating a determination result that a blockage is present in the vapor passage in the determination process when the start remaining amount is larger than or equal to a set value.

A fuel system having a fuel tank, a filler pipe for adding liquid fuel, a carbon canister for collecting fuel vapors from the fuel tank during a refueling operation, a stepper motor and a stepper driven valve for controlling fluid communication between the fuel tank and the canister, where the valve is configured to be positionable in a closed position, an open position creating a passageway with a first size, and one or more intermediate positions each creating a passageway with a size which is smaller than the first size and having a moving element, movable relative to a valve opening between a closed position and an opened position, the moving element having: a sealing means for making a leak tight seal and, a deflecting means for controlling the fluid flow, where the deflecting means protrudes inside the valve opening and is adapted to be located upstream relative to sealing means.

A gas-leak-detection device for detecting a gas leakage from an evaporative emission system includes an electric-wire-connection portion and a passage connection portion that are disposed to overlap with at least one of appearance components in a vehicle when the vehicle is seen in a viewing direction, and are disposed closer to the at least one appearance component than a center plane perpendicular to the viewing direction when the vehicle is in an upright state, the center plane being one of an imaginary-lateral-center plane that is an imaginary vertical plane perpendicular to the left-right direction, an imaginary-longitudinal-center plane that is an imaginary vertical plane including a center in the front-rear direction and being perpendicular to the front-rear direction, or an imaginary-vertical-center plane that is an imaginary horizontal plane including a center in the top-bottom direction and being perpendicular to the top-bottom direction.

An active purge system (APS) according to a driving state of a hybrid vehicle includes an active purge unit (APU) configured to pressurize a vaporized gas generated in a fuel tank of the hybrid vehicle and supply the pressurized vaporized gas to an intake pipe, and a control unit configured to control the APU, where the control unit gradually controls a processing amount of the vaporized gas according to the driving state of the hybrid vehicle. The processing amount of the vaporized gas is gradually controlled using the APS according to the driving state of the hybrid vehicle, particularly, a number of places at which slip occurs in a power transmission system of the hybrid vehicle so that degradation of driving ability due to the occurrence of slip is reduced.

Evaporative emission purge control systems and methods use a cost factor to incentivize operation of an internal combustion at torques favorable for purge. An evaporative emission control system is configured to collect fuel vapor. A controller determines whether an operating speed of the internal combustion engine is within a target purge region that is bounded by a lower speed threshold and an upper speed threshold of the internal combustion engine. When the operating speed of the internal combustion engine is within the target purge region, the controller applies a cost factor to operating points for the internal combustion engine, and based on the cost factor, the operating points are set to include an operating torque for the internal combustion engine to generate an intake pressure of the internal combustion engine at a level below atmospheric pressure for a purge of the evaporative emission control system.

A controller is configured to execute an emission process of, on condition that the number of times a leakage diagnosis of a fuel tank is performed in a stop period from when an internal combustion engine stops to when the engine restarts is less than a predetermined allowable number of times, emitting gas from the fuel tank via a canister by opening a shut-off valve, execute a diagnosis process of performing the leakage diagnosis based on a change in index value, caused by the emission process, the index value indicating a pressure in the fuel tank, and execute a subtraction process of, when fuel has been fed to the fuel tank in a state where the shut-off valve is open in the stop period of the internal combustion engine, reducing the allowable number of times in the stop period in which fuel has been fed to the fuel tank.

A device for controlling purge of a vehicle includes: a state detector detecting state information to control purge of an engine; a controller generating an amount of fuel of each of cylinders of the engine using an amount of air of each cylinder, compensation information, a lambda control value, and an amount of a purge gas of the engine, checking a purge distribution coefficient according to an amount of an intake air for each cylinder when the state information satisfies a control entry condition, generating an amount of redistribution of the purge gas using the amount of the purge gas and the purge distribution coefficient, and generating an injection time for each cylinder using the amount of fuel, a conversion coefficient, and the amount of redistribution of the purge gas; and an injector injecting fuel in each cylinder during the injection time based on control of the controller.