In a control system for an internal combustion engine that can use a plurality of kinds of fuel including compressed natural gas, the invention prohibits a changeover from CNG to another fuel from being made in a period from a time when CNG is used for the first time after the start of the internal combustion engine to a time when it is determined that properties of CNG do not need to be learned, or a period from the time when CNG is used for the first time after the start of the internal combustion engine to a time when a processing of learning the properties of CNG ends.

A portable generator includes an engine including an air-fuel mixing device, an alternator, first and second fuel reservoir fluidly coupled to the air-fuel mixing device, a first fuel valve and a second fuel valve movable to an open position that allows fuel to flow from respective fuel reservoirs to the air-fuel mixing device and a closed position that prevents fuel from flowing from respective fuel reservoirs to the air-fuel mixing device, a fuel selector input device operable to select the first or second fuel reservoir as the source of fuel, and a controller programmed to automatically open or close the first fuel valve and open or close the second fuel valve in response to an input from the fuel selector input device indicating selection of the first or second fuel reservoirs.

A technique for fuel system protection for an internal combustion engine includes introducing a directly injected fuel into a combustion chamber through a direct fuel injector, introducing a fumigated fuel upstream of an intake valve, selectively operating the internal combustion engine with at least one of the directly injected fuel and the fumigated fuel, determining a temperature of the direct fuel injector as a first function of engine operating parameters, and performing a temperature mitigation technique when the temperature rises above a first predetermined value such that the temperature is maintained below a second predetermined value.

Methods and systems are provided for a fuel supply system for an internal combustion engine system, in particular of a motor vehicle, having at least one liquefied petroleum gas (LPG) tank for storing an LPG fuel and at least one direct injection unit, which has a direct injection fuel distributor and direct injection valves that can be supplied with fuel via said distributor. In order to improve supply of the internal combustion engine system with LPG fuel, the fuel supply system includes a booster pump inserted between the LPG tank and the direct injection fuel distributor. A discharge side of the booster pump is connected directly to the direct injection fuel distributor by at least one line, and the direct injection valves each have a closure part that rises outward from a valve seat to open the respective direct injection valve.

On the basis of a decrease in a high-pressure detection value and a low-pressure detection value during fuel control using a CNG injector, an electronic control unit automatically switches the combustion control to combustion control using a gasoline injector even when the amount of CNG remaining is insufficient. When the first shutoff valve is forcibly switched to an closed state by inputting a forcible shutoff command of a first shutoff valve to a terminal and the combustion control using the CNG injector is performed, a switching process to the combustion control using the gasoline injector is inhibited regardless of the decrease in the high-pressure detection value and the low-pressure detection value.

Examples are provided for switching an engine fuel supply. One example system includes a direct-injection engine including a cylinder, an LPG tank for storing a LPG fuel, a CNG tank for storing a CNG fuel, a gas switching valve, a high-pressure pump connected between the LPG tank and the gas switching valve, a pressure-limiting valve connected between the CNG tank and the gas switching valve, a fuel distributor configured to be supplied with one or more of the LPG fuel and the CNG fuel via the gas switching valve, an LPG injection valve coupled to the cylinder, a CNG injection valve coupled to the cylinder, the LPG injection valve and the CNG injection valve configured to be supplied with fuel via the fuel distributor; and a controller configured to control the gas switching valve depending on an aggregate state of the fuel disposed in the fuel distributor.

Methods and systems are provided for integrating a bi-fuel engine with a CVT transmission. Responsive to a driver demand, a controller may determine whether to maintain usage of a current fuel or transition to an alternate fuel based on the cost efficiency of the transition and further based on any engine limitations that may be incurred at the engine speed-load following the transition. To improve the net fuel economy benefit while addressing the engine limitation, a fuel transition may be combined with a CVT adjusted engine speed-load regime, while maintaining engine power output.

A dual fuel injector may be used to inject both gas and liquid fuel into a cylinder of a compression ignition engine. An injector body defines a first set of nozzle outlets, a second set of nozzle outlets, a first fuel inlet and a second fuel inlet. A dual solenoid actuator includes a first armature, a first coil, a second armature and a second coil that share a common centerline. The dual solenoid actuator has a non-injection configuration at which the first armature is at an un-energized position and the second armature is at an un-energized position. The dual solenoid actuator has a first fuel injection configuration at which the first fuel inlet is fluidly connected to the first set of nozzle outlets, the first armature is at an energized position and the second armature is at the un-energized position.

The present invention provides a novel combination of devices to measure and transmit to an electronic controller data pertaining to differential pressures, temperatures, regeneration status, exhaust content, accumulated gas consumption and substitute fuel consumption. The electronic controller compares the data to thresholds; when the controller receives signals indicating these thresholds or limits are met, the controller causes the gas substitution rate to be diminished or set to zero until after-treatments elements are fully regenerated thereby facilitating integration of a mixed fuel system with an application internal combustion engine.

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.