A method of operating an aircraft engine of an aircraft, the aircraft engine having a common-rail fuel injection system for injecting fuel into a combustion chamber of the aircraft engine, including: pressurizing fuel for circulation through the common-rail injection system; circulating a portion of the pressurized fuel through a motive flow inlet of an ejector pump; and entraining a flow through the ejector pump with the portion of the pressurized fuel circulating through the motive flow inlet.

Electronic fuel injection for an internal combustion engine maintains an operator-specified air-to-fuel ratio during engine operations in high-speed, high-volume, mixed fuel applications. A microprocessor-based controller executes a program stored in memory to calculate a fuel flow value as a function of the specified air-to-fuel ratio and specified density ratio of mixed fuels. The controller outputs a control signal to a variable fuel flow relief valve and receives feedback from an engine fuel flow sensor. The controller adjusts the control signal until the feedback matches the fuel flow value. The program optimizes the fuel flow value by accounting for engine air flow, water vapor density, and dry air density effects in the calculation, based on signals received by the controller from various environmental sensors. The system has particular application in dragster engines that burn a mixture of nitromethane and methanol.

Electronic fuel injection for an internal combustion engine maintains an operator-specified air-to-fuel ratio during engine operations in high-speed, high-volume, mixed fuel applications. A microprocessor-based controller executes a program stored in memory to calculate a fuel flow value as a function of the specified air-to-fuel ratio and specified density ratio of mixed fuels. The controller outputs a control signal to a variable fuel flow relief valve and receives feedback from an engine fuel flow sensor. The controller adjusts the control signal until the feedback matches the fuel flow value. The program optimizes the fuel flow value by accounting for engine air flow, water vapor density, and dry air density effects in the calculation, based on signals received by the controller from various environmental sensors. The system has particular application in dragster engines that burn a mixture of nitromethane and methanol.

A fuel delivery system for a vehicle engine and a method are provided. A first valve in parallel with a first fuel pump fluidly couples a fuel line to a fuel tank. A second valve in parallel with a second fuel pump fluidly couples a fuel rail to the fuel line. A controller opens the first and second valves during a vehicle key-off state to relieve pressure in the fuel rail and drain fuel into the fuel tank. A vehicle is provided with a fuel tank, and a valve fluidly coupling a fuel rail and a fuel tank. A controller opens the valve during a vehicle key-off state to drain fuel from the fuel rail into the fuel tank and relieve pressure in the fuel rail, and closes the valve in response to a predicted key-on event during the vehicle key-off state.

An object of the invention is to provide a fuel supply pump that can simultaneously prevent cavitation erosion in a relief valve seat portion at the time of increasing the pressure and reduce a maximum pressure when releasing an abnormally high pressure. Therefore, in the fuel supply pump, a relief valve mechanism includes a seat portion and a relief valve seated on the seat portion, and sets a set discharge pressure to 30 MPa or more. A seat angle of the seat portion is formed to be 40° to 50°, and a set valve opening pressure of the relief valve mechanism is set to 2 MPa or more than the set discharge pressure.

A high pressure fuel pump is provided with a pumping bore and a pressure relief valve only opening to enable a return flow from the outlet conduit back to the compression chamber when the pressure in the outlet conduit exceeds a predetermined threshold. The pressure relief valve is arranged in an elongated pressure relief valve chamber extending parallel and offset to the pumping bore.

A method for monitoring a pressure sensor in a direct injection system including at least one common rail, a high-pressure fuel pump, a hydraulic circuit connecting the high-pressure pump to the common rail, a passive pressure-limiting valve connected to the hydraulic circuit, configured to open once the pressure in the hydraulic circuit is greater than a threshold pressure, so as to discharge the fuel, including the steps of detecting the opening of the pressure-limiting valve, measuring the pressure P.sub.MES corresponding to the time of opening of the pressure-limiting valve and comparing the measured pressure P.sub.MES to the threshold pressure P.sub.1 in order to detect a drift in the pressure sensor.

A method of operating an aircraft engine of an aircraft, the aircraft engine having a common-rail fuel injection system for injecting fuel into a combustion chamber of the aircraft engine, including: pressurizing fuel for circulation through the common-rail injection system; circulating a portion of the pressurized fuel through a motive flow inlet of an ejector pump; and entraining a flow through the ejector pump with the portion of the pressurized fuel circulating through the motive flow inlet.

The invention relates to a high-pressure fuel pump (10) having a housing (12) in which a pressure-limiting valve (38) is arranged in a bore (36), wherein the bore (36) leads into an inflow volume (30) of a low-pressure inflow (22).

An outlet valve includes an outlet valve housing with an outlet valve bore including an outlet valve seating surface. The outlet valve also includes an outlet valve member which moves within the outlet valve bore second portion between a closed position and an open position. A surface of the outlet valve bore guides the outlet valve member during movement between the closed position and the open position. The surface of the outlet valve bore and the outlet valve seating surface are provided on a continuous piece of material of the outlet valve housing. An outlet valve spring biases the outlet valve member toward the closed position and a retainer is fixed to the outlet valve housing which grounds the outlet valve spring to the outlet valve housing.