A method for fuelling an internal combustion engine, and a fuel system (10) for delivering a variety of fuel types to the engine, with selected fuel types typically being chosen according to theft availability. The fuel system (10) can be configured to accommodate liquid fuels such as gasoline, ethanol or a blend thereof, and gaseous fuels such as CNG, LNG or LPG. The engine is configured to operate on any of the designated liquid fuels, and can switch between the liquid and gaseous fuels. The fuel system (10) includes a respective common delivery arrangement (11) for selectively delivering fuel into the combustion chamber of each cylinder of the engine. The common delivery arrangement (11) comprises at a fluid delivery device (12) and a liquid metering device (31) configured for operation in concert. The fluid delivery device (12) comprises a fluid delivery injector. Fuel is delivered to each combustion chamber is through the same fluid delivery device; that is, the same fluid delivery device (12) is used, regardless of the fuel type. More particularly, the fluid delivery device (12) can be used for delivery of gaseous fuel only, delivery of liquid fuel only (by way of an air assist delivery process), or delivery of a fuel mixture comprising the gaseous fuel and the liquid fuel according to the fuelling requirements of the engine at any time.

A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and has an electrical power generator. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off connects to the carburetor to selectively interrupt a flow of liquid fuel to the engine. The liquid fuel cut-off is operable in open and closed states such that the liquid fuel cut-off interrupts the flow of liquid fuel when closed. The dual fuel engine also includes controller operably connected to operate the liquid fuel cut-off in the open and closed states, and the controller may be programmed to implement a delay period upon engine startup before closing the liquid fuel cut-off.

A conventional gasoline engine is retrofitted and calibrated to operate as a bi-fuel engine using Hydrogen as the second fuel. When operated with Hydrogen, which typically leads to a reduction of engine output power, the engine is preferably operated in a charged mode and in a lean mode with the engine throttle kept in a wide-open position during charged and lean mode operation resulting in a more efficient engine with a reduction of engine output power loss.

A method of characterizing a mixed fuel flow period is provided. The method includes flowing a mixed fuel, the mixed fuel being comprised of at least a first fuel type and a second fuel type, the mixed fuel flow period being determined where the fuel is switched from the first fuel type to the second fuel type, determining a density of the first fuel type and a density of the second fuel type, and determining a total flow, the total flow being determined from the density of the first fuel type and the density of the second fuel type.

An internal combustion engine system is described herein. The system uses a switching rail in combination with a first fuel rail to operate the internal combustion engine of the system. The first fuel rail receives the first fuel for combustion within one or more of the combustion cylinders of the internal combustion engine. The switching rails are configured to receive either the first fuel or a second fuel. A controller is used to operate a switching valve that, depending on the position of the switching valve, routes or directs either the second fuel or the first fuel from their respective fuel tanks. In a switching condition, such as startup, shutdown, or when the second fuel is not available, the controller can use the first fuel as the alternate source of fuel provided through the switching rail.

A device is provided, which makes it possible to perform a failure diagnostics for a filter more accurately even in the case of an internal combustion engine which is constructed to be capable of using both of gaseous fuel and liquid fuel. The device of the invention comprises judging means which judges any failure of the filter by comparing the added-up amount of the particulate matter contained in the exhaust gas as detected by a PM amount detecting sensor during a predetermined period and the added-up amount of the particulate matter contained in the exhaust gas as estimated by PM amount estimating means during the predetermined period, wherein the PM amount estimating means estimates the added-up amount of the particulate matter contained in the exhaust gas on the basis of the predetermined parameter and only a fuel injection amount of the liquid fuel out of a fuel injection amount of the gaseous fuel and the fuel injection amount of the liquid fuel.

A combination control assembly of dual fuel internal combustion engine comprises a dial (2) that can be rotated to manipulate operation of a dual fuel internal combustion engine; a turntable (3) includes a disk body (301) and a shift lever (302), characterized in that the shift lever (302) is settled on the disk body (301); a first rotating part (4) that can be rotated by cooperating with the shift lever (302); a second rotating part (9) that can be rotated by cooperating with the shift lever (302); a first fuel valve (6) opened by the first rotating part (4), a second fuel valve (11) opened by the second rotating part (9). The combination control assembly controls the first fuel valve (6) and the second fuel valve (11), simplifying the manual operation and keeping the engine runs stable.

A pump system includes a pump and a storage volume in fluid communication with a discharge port of the pump. The pump includes a housing defining a pump bore and a pump piston disposed in sliding engagement with the pump bore, the pump piston being in selective fluid communication with the discharge port of the pump. A method for operating the pump system includes determining a time to drain an amount of a first fluid from the storage volume, and retracting the pump piston within the pump bore at a target retraction rate based at least partly on the time to drain the first fluid from the storage volume.

An internal combustion engine system is described herein. The system uses compressed air from a compressor to purge at least a portion of a fuel from an internal combustion engine. During a purge operation, a controller opens and closes an injector of the fuel to be purged to allow the compressed air from the compressor to push at least a portion of the fuel back into a fuel tank through the injector. The controller deenergizes a fuel pump that pumps the fuel to be purged, allowing the pressure of the fuel that is to be purged to reduce to a pressure that allows the compressed air to flow into the injector.

A flexible-fuel internal combustion engine apparatus comprises a combustion chamber, an intake valve, a first fuel injector, a second fuel injector, and a computer. The intake valve is operable to admit an intake charge into the combustion chamber. The first fuel injector injects a gaseous fuel directly into the combustion chamber. The second fuel injector injects a liquid fuel into the intake charge upstream of the intake valve. The computer is operatively connected with the first fuel injector and the second fuel injector to actuate injection of fuel respectively therefrom. The computer is programmed to command a gaseous-to-liquid fuel ratio as a function of at least one operating parameter from a group comprising gaseous fuel pressure, gaseous fuel mass, engine speed, engine torque, inlet air temperature, inlet air humidity, knock detection, operating history, torque command, and emissions.