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.

Systems and methods are provided herein for tracking degradation of a high-pressure fuel pump. In one example, a fuel system controller is configured to receive an output pressure signal from a pressure sensor, transform the output pressure signal to the frequency domain to generate frequency content of the output pressure signal, and diagnose a condition of a fuel pump based at least in part on the frequency content of the output pressure signal, the fuel pump fluidly coupled to a fuel injector via a common fuel rail, and the fuel injector is operable to inject fuel to a cylinder of an engine.

A high pressure fuel pump includes: a pump body that forms a suction passage and a pressurizing chamber and slidably supports a plunger; and a control valve that opens a connection between the suction passage and the pressurizing chamber in a suction stroke, during which the plunger is driven toward a suction side for suctioning fuel into the pressurizing chamber, while the control valve controls closing timing, at which the connection between the suction passage and the pressurizing chamber is closed by the control valve in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber. The pump body forms a release passage that is communicated with the suction passage. The release passage relieves the fuel, which is pressurized by the plunger, from the pressurizing chamber before the closing timing during the delivery stroke.

A high pressure fuel pump includes: a pump body that forms a suction passage and a pressurizing chamber and slidably supports a plunger; and a control valve that opens a connection between the suction passage and the pressurizing chamber in a suction stroke, during which the plunger is driven toward a suction side for suctioning fuel into the pressurizing chamber, while the control valve controls closing timing, at which the connection between the suction passage and the pressurizing chamber is closed by the control valve in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber. The pump body forms a release passage that is communicated with the suction passage. The release passage relieves the fuel, which is pressurized by the plunger, from the pressurizing chamber before the closing timing during the delivery stroke.

Unclogging group for unclogging a filter of a pumping group for pumping diesel to an internal combustion engine, the unclogging group (1) comprising: —a metering unit (2) supplied by diesel leaving a low pressure pump and configured for feeding in a controlled manner the diesel to a high pressure pump; the metering unit (2) comprising an electromagnetic head (4) provided with a coil (6) and a control valve (5) for controlling the diesel flow; —a filter (30) associated with the control valve (5); —a temperature sensor (34) for measuring the ambient temperature; —a control unit (31) coupled at one side to the temperature sensor (34) and at another side to the coil (6); wherein the control unit (31) is configured so that once it has received the starting input of the pumping group it compares the temperature measured by the temperature sensor (34) with a threshold value, and if the temperature measured by the temperature sensor (34) is less than the threshold value the control unit (31) commands a delay of the starting of the pumping group of a period wherein the control unit (31) supplies electrical current to the coil (6).

Unclogging group for unclogging a filter of a pumping group for pumping diesel to an internal combustion engine, the unclogging group (1) comprising: —a metering unit (2) supplied by diesel leaving a low pressure pump and configured for feeding in a controlled manner the diesel to a high pressure pump; the metering unit (2) comprising an electromagnetic head (4) provided with a coil (6) and a control valve (5) for controlling the diesel flow; —a filter (30) associated with the control valve (5); —a temperature sensor (34) for measuring the ambient temperature; —a control unit (31) coupled at one side to the temperature sensor (34) and at another side to the coil (6); wherein the control unit (31) is configured so that once it has received the starting input of the pumping group it compares the temperature measured by the temperature sensor (34) with a threshold value, and if the temperature measured by the temperature sensor (34) is less than the threshold value the control unit (31) commands a delay of the starting of the pumping group of a period wherein the control unit (31) supplies electrical current to the coil (6).

An object of the present invention is to supply a high-pressure fuel supply pump capable of holding a spring holding member while reducing the height of the pump body. A high-pressure fuel supply pump is provided with a pump body for forming a pressurizing chamber at an inner wall portion, and a flange portion for fixing the pump body to a high-pressure fuel supply pump mounting portion. The high-pressure fuel supply pump is provided with a cylinder and a spring holding member. The cylinder is inserted into a hole portion of the pump body from a lower side and in which the pressurizing chamber is formed further above an uppermost end surface. The spring holding member has an outer peripheral portion press-fitted and fixed to the pump body and a holding portion holding a spring portion for biasing the pump body between the outer peripheral portion and the inner peripheral portion. A spring-side lowest end portion of the holding surface of the spring holding member is disposed above the lowermost end portion of the flange portion.

An object of the present invention is to supply a high-pressure fuel supply pump capable of holding a spring holding member while reducing the height of the pump body. A high-pressure fuel supply pump is provided with a pump body for forming a pressurizing chamber at an inner wall portion, and a flange portion for fixing the pump body to a high-pressure fuel supply pump mounting portion. The high-pressure fuel supply pump is provided with a cylinder and a spring holding member. The cylinder is inserted into a hole portion of the pump body from a lower side and in which the pressurizing chamber is formed further above an uppermost end surface. The spring holding member has an outer peripheral portion press-fitted and fixed to the pump body and a holding portion holding a spring portion for biasing the pump body between the outer peripheral portion and the inner peripheral portion. A spring-side lowest end portion of the holding surface of the spring holding member is disposed above the lowermost end portion of the flange portion.

To increase a valve-opening pressure at which a pressure relief valve is opened in order to deal with a higher pressure of the fuel, a large pressure relief valve is installed in a high-pressure fuel supply pump. This upsizes the high-pressure fuel supply pump. A pressure relief valve is installed in a discharge joint. This can provide a high-pressure fuel supply pump that is not large too much and sufficiently performs a relief function by efficiently using the excessive space in the pump even when the fuel pressure is increased.

To increase a valve-opening pressure at which a pressure relief valve is opened in order to deal with a higher pressure of the fuel, a large pressure relief valve is installed in a high-pressure fuel supply pump. This upsizes the high-pressure fuel supply pump. A pressure relief valve is installed in a discharge joint. This can provide a high-pressure fuel supply pump that is not large too much and sufficiently performs a relief function by efficiently using the excessive space in the pump even when the fuel pressure is increased.