A method is provided, comprising indicating a fuel vapor canister load based on a steady-state pressure in a vapor recovery line during a refueling event; and adjusting a canister purging operation in response to the indicated fuel vapor canister load. Restrictions in the vapor recovery line may increase the rate of fuel vapor canister loading during a refueling event. In this way, an accurate canister load may be determined following a refueling event, and canister purging operations adjusted accordingly.

A control device of an internal combustion engine including an electronic control unit configured to execute: a base injection amount calculation process of calculating a base value; an injection valve operation process of operative the fuel injection valve; a feedback process of correcting an injection amount in the injection valve operation process; and a determination process of determining whether or not the amount of fuel flowing into the cylinders other than fuel injected from the fuel injection valve is equal to or larger than a threshold value. When it is determined as a result of the determination that the amount of fuel flowing into the cylinders other than the fuel injected from the fuel injection valve is equal to or larger than the threshold value, the electronic control unit (does not execute the process of injecting fuel from the fuel injection valve with the feedback process stopped.

A fuel vapor treating apparatus includes a canister, a purge pipe, a purge control valve, and a heating device. The canister is configured to store fuel vapor generated in a fuel tank. The purge pipe is configured to deliver the fuel vapor stored in the canister to an intake passage of an internal combustion engine together with air. The purge control valve is configured to be attached to the purge pipe to be selectively opened and closed in order to adjust a purge flow rate. The purge control valve is also configured to be opened based on a purge request that is made after the internal combustion engine is started. The heating device is configured to heat the purge control valve after the internal combustion engine is started and before the purge request is made.

A vaporized-fuel treating apparatus is configured to perform purge control in which a purge valve is placed in an open state while a purge pump is being driven to introduce purge gas from a canister to an intake passage through a purge passage. When an actual value of a flow rate of the purge gas during execution of the purge control is defined as an actual purge flow rate, and an upper-limit value of the purge flow rate to prevent the occurrence of A/F disturbance where A/F in a combustion chamber of an engine excessively fluctuates, as an upper-limit purge flow rate, the number of rotations of the purge pump is controlled during execution of the purge control to adjust the actual purge flow rate to a value equal to or lower than the upper-limit purge flow rate.

An engine apparatus includes an engine, a supercharger, an evaporated fuel treatment device, a controller and the engine apparatus is configured to determine a purge classification whether the evaporated fuel is a first purge in which the evaporated fuel flows dominantly in a first purge passage or a second purge in which the evaporated fuel flows dominantly in a second purge passage based on a relative ejector pressure that is a pressure of a suction port of the ejector and a value obtained by adding an offset amount based on a cross-sectional area of the second purge passage with respect to a cross-sectional area of the first purge passage to a pressure behind a throttle valve that is the pressure on a downstream side of the throttle valve of the intake pipe.

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.

Methods and systems are provided for managing fuel vapor in a vehicle evaporative emissions system configured with a fuel vapor canister for capturing and storing vapors from a vehicle fuel tank. In one example, a three-way valve is positioned between the fuel vapor canister and atmosphere, and may function during engine-off conditions to direct fuel tank vapors through the fuel vapor canister where they may be adsorbed, and then to an intake manifold of the engine where a second adsorbent for capturing and storing fuel vapors is positioned. In this way, fuel vapors that are not adsorbed by the fuel vapor canister, or fuel vapors that are freed from the canister during engine-off conditions may be routed to the second adsorbent prior to exiting to atmosphere, thus reducing undesired bleed emissions.

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.

Methods and systems are provided for coordinating throttle bypass flows from brake booster vacuum reservoir, a fuel vapor purge system, and a crankcase ventilation system via active, electrical control of a crankcase ventilation valve. In one example, a method may include actively opening the crankcase ventilation valve to allow crankcase ventilation flow into the engine during conditions in which doing so will not result in engine air flow rate and/or engine fuel flow rate exceeding desired rates. Priority is given first to brake booster replenishment, then to fuel vapor purging, and then to crankcase ventilation during conditions where all three throttle bypass flows are desired.

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.