Abstract: When a leak test for a purge pipe and a vapor pipe as targets is executed, a sealing valve that is being closed is opened while an open state of a bypass valve is kept prior to the execution of the leak test, fuel evaporative gas in a fuel tank is caused to flow out to a canister side to reduce a tank internal pressure Ptan to a valve opening guarantee determination value P0, and after the bypass valve is closed subsequently, the leak test is started.

Abstract: 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.

Abstract: A method for a fuel system, comprising: indicating a leak in a fuel tank following applying a vacuum to the fuel tank by running a vacuum pump in a first direction; then purging a fuel vapor canister to the fuel tank by running the vacuum pump in a second direction, opposite the first direction. In this way, the fuel vapor canister may be purged of its contents following a fuel system leak check. This may reduce bleed emissions while increasing the efficiency of the vehicle, as the engine does not need to be turned on in order to purge the canister.

Abstract: Methods and systems are provided for controlling canister purge flow in a boosted engine. An example method for the boosted engine comprises, during boosted conditions, flowing stored fuel vapors from a canister into an ejector coupled in a compressor bypass passage, the flowing bypassing a canister purge valve. The method further comprises, responsive to a canister load higher than a threshold load, closing a canister vent valve coupled to the canister, and discontinuing flowing stored fuel vapors from the canister into the ejector.

Abstract: Methods and systems are provided for controlling the purging of a fuel vapor canister coupled to a vehicle fuel tank, configured for capturing and storing vapors emanating from the tank. In one example, two canister purge valves are coupled in series in a fuel vapor conduit between the fuel vapor canister and engine intake, one at the intake manifold and one at the fuel vapor canister, such that fine control over the introduction of fuel vapors into the engine is maintained via the purge valve at the intake manifold, while thorough purging of the fuel vapor canister may be regulated via the purge valve at the fuel vapor canister. In this way, fuel vapors in the fuel vapor canister may be effectively purged to intake, thus reducing the potential for undesired evaporative emissions.

Abstract: A saddle-riding type vehicle includes a seat, a fuel tank including a vent and disposed below the seat, a canister connected to the vent, and an overflow prevention valve provided in a fuel vapor passage connecting the vent and the canister. The overflow prevention valve is positioned higher than the vent.

Abstract: A system according to the present disclosure includes a valve control module, a purge fraction module, and a diagnostic module. The valve control module opens a purge valve in an evaporative emissions system to allow purge vapor to flow to an intake system of an engine. The purge fraction module determines first and second fractions of purge vapor delivered to the engine relative to a total amount of air and purge vapor delivered to the engine based on first and second inputs, respectively. The first input is from a hydrocarbon sensor disposed in the evaporative emissions system of the engine. The second input is from an oxygen sensor disposed in an exhaust system of the engine. The diagnostic module selectively diagnoses a fault in at least one of the evaporative emissions system and the hydrocarbon sensor based on the first and second purge fractions when the purge valve is open.

Abstract: A method for localizing restrictions in a fuel system during refueling, comprising: monitoring fuel tank pressure, fuel vapor canister temperature, and evaporative leak check module pressure during a refueling event; and responsive to a premature shutoff event, indicating a location of a restriction among a plurality of locations based on whether monitored pressure and temperature changes during the refueling event are greater than respective thresholds. In this way, the cause of a premature shutoff event may be diagnosed without requiring additional sensors within the fuel system.

Abstract: Embodiments for controlling fuel vapors are disclosed. In one example, a method comprises during a purge of a fuel vapor canister, adjusting a heater of the fuel vapor canister based on a rate of a purge flow exiting the fuel vapor canister and a concentration of hydrocarbons released from the fuel vapor canister. In this way, a fuel vapor canister purge efficiency may be increased.

Abstract: Methods and systems are provided for improving the efficiency of canister purge completion. Based on engine operating conditions, a canister is purged to a compressor inlet or a throttle outlet. During purging conditions, as canister loads change, a purge flow through the canister is varied so that a fixed preselected portion of total engine fueling is delivered as fuel vapors.

Abstract: Systems and methods for diagnosing individual components of an evaporative emissions system are presented. In one example, fuel vapor flow may be a basis for determining whether or not selected emission system components may be degraded. Further, fuel tank pressure may be another basis for determining component whether or not selected emissions system components may be degraded.

Abstract: An evaporative fuel processing apparatus executes a purge process when a predetermined purge condition is satisfied. A precondition, which is satisfied immediately before the satisfaction of the purge condition, is set. An operation of a purge pump is started at the time of satisfying the precondition. Thereafter, when the purge condition is satisfied, the purge valve is opened to execute the purge process. In this way, the time required for the purge pump to reach a rated rotational speed upon satisfaction of the purge condition can be shortened. Thus, the operating time period of the purge pump can be shortened, and the response delay of the purge can be avoided. That is, it is possible to limit shortage of the purge amount caused by the response delay.

Abstract: A controller for an internal combustion engine is provided. The engine includes a compressor, a three way catalyst, a canister, an evaporated fuel passage, an ejector, and a purge control valve. The controller includes an ECU. The ECU is configured to decrease an opening degree of the purge control valve in response to an increase in pressure on the downstream side of the compressor in a lean supercharging range. The is a range in which an operation air-fuel ratio of the internal combustion engine is leaner than a theoretical air-fuel ratio of the internal combustion engine, and in which the pressure on the downstream side of the compressor is higher than pressure on the upstream side of the compressor.

Abstract: An evaporation fuel purge system includes: a fuel tank; a canister that absorbs and desorbs evaporation fuel emitted from the fuel tank; an intake passage for an internal combustion engine in which the evaporation fuel desorbed from the canister is mixed with fuel for combustion; a purge passage that connects the canister to the intake passage; an ejector device disposed in the purge passage; and a fluid drive device. The ejector device has a nozzle part that accelerates external fluid. The fluid drive device sends outside air corresponding to the external fluid to flow into the nozzle part.

Abstract: A vaporized fuel processing apparatus for an engine, which includes an intake passage equipped with a supercharging device and a throttle valve, has an adsorbent canister and a purge passage. The adsorbent canister is adapted to communicate with a fuel tank. The purge passage communicates the adsorbent canister with the intake passage of the engine. The purge passage has in series a purge valve for controlling communication through the purge passage and a purge pump for generating gas flow from the adsorbent canister toward the intake passage. The purge passage includes a sub-passage for communicating the adsorbent canister with the intake passage without passing through the purge pump. The purge passage divides into a first passage connected to the intake passage downstream of the throttle valve and a second passage connected to the intake passage upstream of the supercharging device.

Abstract: A fuel vapor storage and recovery apparatus (1) comprising at least one main vapor storage compartment (3) filled with an adsorbent material, at least one vapor inlet port (7), at least one atmospheric vent port (8), and at least one purge port (9). The vapor inlet port (7) being connectable to a fuel tank venting line and the purge port (9) being connectable to an engine air intake line, wherein the main vapor storage compartment (3) comprises a purge buffer zone (14) as well as first vapor distribution chamber (10), wherein the first fuel vapor distribution chamber (10) includes a liquid trap.

Abstract: 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.

Abstract: An engine controller includes: a warm-up control unit that performs warm-up operation for letting the engine continuously operate until an integration value of air intake of the engine comes to a predetermined integration value in order to warm up a catalyst provided in an exhaust system when the engine is first started after start-up of the vehicle; and a continuation control unit that lets the engine continuously operate for a predetermined period subsequent to an end of the warm-up operation. The continuation control unit takes an output value of the engine as a request output value when the request output value of the engine is a predetermined idling output value or more that is smaller than the predetermined warm-up output value and takes the output value as the warm-up output value when the request output value is less than the predetermined idling output value.

Abstract: Methods and systems for fuel system leak detection using passive canister vent valves are disclosed. In one example approach, a method comprises generating engine off vacuum or pressure in a fuel system for leak diagnostics, where the pressure and vacuum are held via first and second mechanical relief valves positioned in parallel with one another and without a valve holding current.

Abstract: A valve assembly, such as a canister purge solenoid (CPS) having one or more interchangeable components which may be used to reconfigure the valve assembly to have one or more additional vacuum ports. The design of the valve assembly eliminates the need to mold these ports into the intake manifold, simplifying the design of the manifold, and the tooling needed to make the manifold. The direct mount design of the CPS of the present invention includes at least one additional port to serve as an additional vacuum port to be used for any other purpose, such as a PCV valve, brake booster, or the like.

Abstract: Methods and systems for cleaning a capless refueling system in a vehicle are disclosed. In one example approach, a method comprises, in response to a leak detected following a refueling event, cleaning the capless refueling system using engine vacuum.

Abstract: A fuel injection control device of an engine is disclosed, that is provided with a fuel injection valve configured to inject a fuel according to a target pulse width into an intake passage, an intake flow rate detection unit arranged to detect a flow rate of an intake air supplied to the engine, an intake pressure detection unit arranged to detect an intake pressure in the intake passage, a fuel pressure detection unit arranged to detect a pressure of a fuel supplied to the fuel injection valve, and a pressure control unit configured to control the fuel pressure according to an engine operation state.

Abstract: A purge pump is installed in a purge conduit, which forms a purge passage that communicates between an inside of a canister and an air intake passage. When a pressure of the air intake passage is equal to or smaller than a predetermined pressure, a large quantity of evaporative fuel, which is larger than a predetermined purge quantity, is introduced into the air intake passage. At this time, a pump electric power supply device supplies a relatively small amount of the electric power to the purge pump to run the purge pump. When the pressure of the air intake passage is larger than the predetermined pressure, the purge pump is driven to pump the evaporative fuel into the air intake passage. At that time, the pump electric power supply device supplies a relatively large amount of the electric power to the purge pump.

Abstract: A fuel vapor treatment apparatus of a vehicle in which a supercharger that supercharges intake air is provided at an intake passage of an internal combustion engine includes a pump controller that drives a pump, a gas passage pressure detector that is provided between a canister and the pump in a gas passage and detects pressure of the gas passage, and an abnormality determining module that determines whether an upstream-side purge passage has an abnormality, on the basis of the pressure detected by the gas passage pressure detector. The pump controller drives the pump when an upstream-side valve is in an opened state. The abnormality determining module determines whether the upstream-side purge passage has an abnormality, on the basis of the pressure detected by the gas passage pressure detector after the upstream-side valve enters the opened state and the pump is driven.

Abstract: The present disclosure provides a solenoid valve and associated method of control for compensated performance based on environmental conditions and optionally product life. The solenoid coil power consumption is proactively optimized based on predetermined database information to cross reference a given operating temperature and optionally, valve operating cycles. The net effect is to reduce power consumption under normal conditions and selectively apply higher power to the valve coil when required.

Abstract: A method for a fuel system is provided. A vacuum is applied to a fuel vapor canister side of the fuel system, and hydrocarbon breakthrough is indicated responsive to a fuel vapor canister side pressure inflection point indicative of a decay in fuel vapor canister side vacuum. In this way, an evaporative leak check module may perform a leak check on a fuel vapor canister, while hydrocarbon breakthrough from the fuel vapor canister may be indicated without requiring a dedicated hydrocarbon sensor in the canister vent line.

Abstract: A method for a vehicle, comprising: during a first condition, closing a canister vent valve responsive to an engine-off event without initiating an engine-off natural vacuum test; during a second condition, following the first condition, closing the canister vent valve responsive to a vehicle-off event; and then initiating an engine-off natural vacuum test. In this way, the completion percentage of the engine-off natural vacuum test will increase.

Abstract: A method for a fuel system, comprising: during a first condition, fluidly coupling a fuel tank to a fuel vapor canister; and fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump. By fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump, the fuel tank may be depressurized slowly without requiring a multi-stage or multi-valve fuel tank isolation system. In this way, the cost and complexity of the fuel system is reduced.

Abstract: A method for supplying fuel to an engine is disclosed. The method may include regulating a gas admission valve disposed between a gaseous fuel line and a cylinder intake port to reduce flow of gaseous fuel to the cylinder. The method may also include closing a shut-off valve disposed between a gaseous fuel reservoir and the gaseous fuel line to restrict flow of gaseous fuel from the gaseous fuel reservoir to the gaseous fuel line. Further, the method may include actuating an inert gas inlet valve disposed between an inert gas reservoir and the gaseous fuel line to supply inert gas to the gaseous fuel line and flush the gaseous fuel in the gaseous fuel line into the cylinder via the gas admission valve. Additionally, the method may include closing the inert gas inlet valve to restrict supply of inert gas to the gaseous fuel line.

Abstract: A control apparatus for an engine introduces purge gas containing fuel gas evaporated from a fuel tank into an intake system includes an air-fuel ratio calculation unit that calculates an air-fuel ratio (AF) of the engine, and a purge rate calculation unit that calculates a purge rate (RPRG) corresponding to an introduction rate of the purge gas. The control apparatus further includes a concentration calculation unit that calculates a concentration (KAF_PRG) of the purge gas based on the air-fuel ratio (AF) calculated by the air-fuel ratio calculation unit and the purge rate (RPRG) calculated by the purge rate calculation unit. A decision unit permits or inhibits the concentration calculation unit to calculate the concentration (KAF_PRG) based on the purge rate (RPRG) calculated by the purge rate calculation unit. The estimation accuracy of the concentration (KAF_PRG) of purge gas is improved.

Abstract: Systems and methods are provided for controlling a purging operation of a fuel vapor canister in a boosted engine. One method comprises purging stored fuel vapors from the fuel vapor canister to an inlet of the compressor via an ejector while bypassing a canister purge valve, the ejector being fluidically coupled to the fuel vapor canister by a distinct passage and motive flow through the ejector being regulated by a shut-off valve. The shut-off valve is temporarily closed in response to an operator tip-in event to discontinue the purging operation.

Abstract: A method for a fuel system, comprising: during a first condition, purging fuel vapor from a fuel vapor canister to a fuel vapor accumulator; and then during a second condition, evacuating fuel vapor from the fuel vapor accumulator to a fuel tank. The fuel vapor accumulator increases the volume of the fuel system, providing a temporary storage for desorbed fuel vapor. In this way, canister breakthrough of hydrocarbons can be mitigated, thereby reducing bleed emissions.

Abstract: A method for a fuel system is presented, comprising directing purge air through a first fuel vapor canister but not a second fuel vapor canister based on a load of the first fuel vapor canister being greater than a threshold. In this way, purging of the first canister may be prioritized and completed without passing desorbed fuel vapors through the second canister, thereby reducing the amount of time needed to purge the first canister, and reducing overall emissions.

Abstract: A resonator (12) for reducing intake air noise is connected to an intake air duct (6) connecting a throttle chamber (5) and an air cleaner case (7). This blow-by gas treatment device is equipped with a fresh air introduction passage comprising a fresh air introduction hose (16), and a blow-by gas passage comprising a blow-by gas hose (20), with the fresh air introduction hose (16) connecting a cylinder head cover (4) and the resonator (12). A connector part (15) of the resonator (12) to which the fresh air introduction hose (16) is connected is provided with an orifice (21) formed integral with a lower body (13) formed of a synthetic resin, as a part thereof. Pulsation is effectively reduced by the throttling effect of the orifice (21) and the expansion effect of the resonator (12).

Abstract: An engine-driven generator that controls fuel vapor flow is provided. The engine-driven generator includes an engine having an air intake, wherein the engine is configured to drive a generator. The engine-driven generator also includes a fuel tank coupled to the engine and configured to provide fuel to the engine. The engine-driven generator includes a valve coupled between the air intake of the engine and the fuel tank. The engine-driven generator also includes a control device configured to transition the valve between a first position and a second position. The first position allows fuel vapor to flow between the fuel tank and the air intake of the engine and the second position inhibits the fuel vapor from flowing between the fuel tank and the air intake of the engine.

Abstract: A purge solenoid valve is opened to introduce an atmospheric pressure into a fuel tank, the purge solenoid valve is closed to operate a negative pressure pump, and set an internal pressure of the tank to a reference pressure Pb. Then, a changeover valve is closed, and the purge solenoid valve is opened to cause a canister to communicate with an intake passage. Further, the changeover valve is opened, and the purge solenoid valve is closed. Then, a first tank internal pressure Po is detected and subtracted from the reference pressure Pb. If a calculated first pressure deviation ?Po is larger than a first threshold ?P1, it is determined that there is no open sticking in a sealing valve.

Abstract: The invention refers to a fuel vapor storage and recovery apparatus comprising a housing (2) defining at least first and second compartments, at least one compartment being filled with an adsorbent material, at least one tank port (5) connectable to a fuel tank vent line, at least one atmospheric vent port (7), an outer housing member (8) defining a first outer compartment (3), an inner housing member defining a second inner compartment (4), the first outer compartment (3) encompassing the second inner compartment (4), wherein the inner housing member (9) is fitted into the outer housing member (8) at one end of the housing (2), such that a wall (13) of the inner housing member (9) engages an inner wall of the outer housing member (8) and wherein the inner housing member (9) and the outer housing member (8) are sealed against each other by means of a closure cap (14).

Abstract: An evaporated-fuel processing apparatus including: a sealing valve which is arranged in a communication path between the atmosphere and a fuel tank mounted on a vehicle having an internal combustion engine, and shuts an internal space of the fuel tank off from the atmosphere; an open/close member which covers a fuel filling port of the fuel tank; a refueling-intention-information acquisition unit which acquires information indicating an intention of refueling; and a control unit which issues an opening command for opening the sealing valve when the refueling-intention-information acquisition unit acquires the information indicating an intention of refueling, and allows the open/close member to open when a time elapsed from the moment at which the opening command is issued exceeds a first predetermined time.

Abstract: A system and method controls a flow of vent gases to a combustion engine. The system includes an inlet for receiving the vent gases, a pressure relief device that enables the vent gases to escape to atmosphere when a pressure in the inlet exceeds a predetermined relief pressure, a flow-restricting orifice, and a back pressure regulator disposed downstream of the orifice. A shut-off valve disposed between the back pressure regulator and the air intake is set to only open when an intake pressure falls below a predetermined negative intake pressure.

Abstract: The invention refers to a fuel vapor storage and recovery apparatus (1) comprising at least one main vapor storage compartment (3) filled with an adsorbent material, at least one vapor inlet port (7), at least one atmospheric vent port (8) and at least one purge port (9), said vapor inlet port (7) being connectable to a fuel tank venting line and said purge port (9) being connectable to an engine air intake line, wherein said main vapor storage compartment (3) comprises a purge buffer zone (14) as well as first and second fuel vapor distribution chambers (10, 24) not filled with an adsorbent material. Said first fuel vapor distribution chamber is arranged upstream said purge buffer zone (14) and communicates with said fuel vapor inlet port (7). Said second fuel vapor distribution chamber (24) is arranged downstream said purge buffer zone and communicates with said purge port (9).

Abstract: Methods and systems are provided for diagnosing a purge path ejector used for purging fuel vapors from a canister under boosted engine conditions. The response of an exhaust gas sensor is monitored during each of vacuum purging of the canister and a subsequent boost purging of the canister, and compared to stoichiometry, to diagnose the ejector. By relying on changes in the exhaust air-fuel ratio incurred during purging, the coupling of the ejector to the compressor inlet may be diagnosed without the need for additional sensors or hardware.

Abstract: A control method for exhaust gas recirculation of a hybrid electric vehicle includes detecting a pressure of an intake manifold. A difference between the pressure of the intake manifold and atmospheric pressure is determined. A load of an engine, which generates torque by combusting a fuel and external air supplied through the intake manifold, is determined. An opening rate of an exhaust gas recirculation valve is controlled to be a first value according to a rotational speed of the engine when the difference is smaller than or equal to a reference pressure and the load of the engine is smaller than or equal to a reference load.

Abstract: Methods and systems are provided for relieving excess fuel tank vacuum in a vehicle. In one example, responsive to a fuel tank vacuum above a threshold or a rise in fuel tank vacuum level being higher than a threshold rate, a canister purge valve is opened to dissipate the fuel tank vacuum into an engine intake manifold while the engine is combusting, and the amount of intake air inducted into the intake manifold is adjusted such that air/fuel ratio errors are reduced. In this way, fuel tank vacuum may be relieved under engine operating conditions wherein the likelihood of air/fuel ratio errors are high, thus enabling rapid relief of fuel tank vacuum such that fuel tank degradation can be reduced and fuel system integrity can be better maintained.

Abstract: An isolation valve may include a flow restrictor disposed in a passage having non-parallel sides, the flow restrictor having an orifice. A flow restrictor spring may apply a biasing force on the flow restrictor to bias the flow restrictor to an open position. A solenoid assembly may include having a coil and an armature that may be moveable between (i) an extended position that overcomes the biasing force of the restrictor spring to move the flow restrictor to a closed position and to close the second orifice, and (ii) a retracted position to open the orifice. If the coil is energized, the armature may move to the retracted position to allow vapor to flow through the orifice at least until the biasing force of the flow restrictor spring overcomes a vapor pressure. The open position of the flow restrictor may allow vapor to flow through a space between the flow restrictor and the passage.

Abstract: A fuel tank structure comprising a fuel tank; a canister that adsorbs evaporated fuel within the fuel tank, and that releases vapor after adsorption of evaporated fuel; a full tank regulating valve within the fuel tank that becomes a closed state due to a float floating in fuel when a fuel liquid surface reaches a full tank liquid level that is set in advance; a communication pipe that communicates the fuel tank and the canister via the full tank regulating valve, a cross-sectional area varying valve that, when tank internal pressure that is applied from inside of the fuel tank increases, reduces a cross-sectional area of a flow path of vapor that flows toward the float; and a suppressing member that is positioned between the cross-sectional area varying valve and the float, and that suppresses airflow from the cross-sectional area varying valve from directly abutting the float.

Abstract: A method of testing an engine fuel supply cutoff valve includes: detecting a fuel supply cutoff command; commanding to close the fuel supply cutoff valve; commanding to hold the fuel metering valve in the open position for a predetermined time; commanding to close the fuel metering valve after the predetermined time; measuring an engine operating parameter during performance of the previous steps; and comparing the measured parameter with a predetermined threshold, so as to determine whether or not the engine operating parameter corresponds to an engine fuel supply cutoff by normal operation of the fuel supply cutoff valve.

Abstract: A liquid submerged portion fuel leakage diagnostic apparatus includes a tank internal pressure detection portion; a liquid level detection portion; a reference-state liquid level extraction portion configured to extract, as a reference-state liquid level, a liquid level detected by the liquid level detection portion, when a tank internal pressure detected by the tank internal pressure detection portion becomes equal to a reference internal pressure; a fuel consumption detection portion configured to detect consumption of fuel in a fuel tank; and a fuel leakage diagnostic portion configured such that if the fuel consumption is not detected by the fuel consumption detection portion during a period between extraction timings at which the reference-state liquid levels are extracted by the reference-state liquid level extraction portion, the fuel leakage diagnostic portion diagnoses presence or absence of fuel leakage from a liquid submerged portion based on comparison of the reference-state liquid levels.

Abstract: [Subject] A low-cost and brief method to detect an airtight failure in a working-gas circulating type gas engine with sufficient accuracy and a working-gas circulating type gas engine using the method should be provided. [Means for Solution] In a working-gas circulating type gas engine, an extra predetermined quantity 1 of at least one of fuel gas, oxidizer gas, and working gas is supplied as surplus gas into a circulation passage. Based on the difference between this predetermined quantity 1 and increment of this predetermined quantity 1 and the increment of the quantity of the gas in the circulation passage separately detected by a gas quantity detecting means, the existence of an airtight failure in the engine is judged.

Abstract: A method for a fuel system is provided, comprising: during a first engine-off condition, coupling a fuel tank to a fuel vapor canister, and indicating degradation based on a change in pressure at the fuel vapor canister, and during a second engine-off condition, coupling the fuel vapor canister to an intake of an engine, and indicating degradation based on a change in pressure at the fuel vapor canister. The first engine-off condition may include an absolute fuel tank pressure greater than a threshold, while the second engine-off condition may include an engine spinning unfueled. In this way, a vacuum or pressure may be applied to the fuel vapor canister during an engine-off condition without requiring a dedicated vacuum pump coupled to the fuel vapor canister.

Abstract: A controlling apparatus for an engine includes a purge path connected to a sealing-type fuel tank and an intake system of an engine and is configured to allow purge gas containing evaporated fuel from the fuel tank to flow therethrough. A purge valve placed in the purge path is configured to adjust a flow rate of the purge gas. A calculation unit calculates a degree of opening of the purge valve based on a target introduction ratio of the purge gas, and a controlling unit controls the purge valve so as to establish the degree of opening calculated by the calculation unit. The calculation unit corrects, in high-pressure purge performed when a pressure in the fuel tank increases exceeding a predetermined pressure, the degree of opening using a tank pressure flow velocity correction coefficient K2 corresponding to an upstream pressure of the purge valve.