A booster pump increases fuel pressure in a high-pressure system of a fuel supply system. A decompression mechanism reduces the fuel pressure. In case of a discharge abnormality of the booster pump which causes rise in the fuel pressure, the fuel pressure control system performs an abnormality handling to cause the decompression mechanism to stop the rise in the fuel pressure. In case of the discharge abnormality, and on determination of a warning-required state, in which the fuel pressure in the high-pressure system possibly exceeds a threshold pressure, a control device causes a warning state, in which the fuel pressure does not exceed the threshold pressure before the rise in the fuel pressure stops, even if the discharge abnormality occurs.

Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.

A control device is included in a fuel injection system. The fuel injection system includes a low pressure pump, a high pressure pump, an accumulator, a fuel injection valve, a relief valve, and a return pipe. The high pressure pump increases a pressure of a fuel discharged from the low pressure pump and discharges high pressure fuel. The accumulator stores the high pressure fuel discharged from the high pressure pump. The relief valve is provided in a high pressure portion provided downstream from the high pressure pump and opens when a high pressure abnormality occurs in the high pressure portion. The return pipe returns the high pressure fuel in the high pressure portion to a low pressure portion provided downstream from the low pressure pump by the relief valve opening.

A control device is included in a fuel injection system. The fuel injection system includes a low pressure pump, a high pressure pump, an accumulator, a fuel injection valve, a relief valve, and a return pipe. The high pressure pump increases a pressure of a fuel discharged from the low pressure pump and discharges high pressure fuel. The accumulator stores the high pressure fuel discharged from the high pressure pump. The relief valve is provided in a high pressure portion provided downstream from the high pressure pump and opens when a high pressure abnormality occurs in the high pressure portion. The return pipe returns the high pressure fuel in the high pressure portion to a low pressure portion provided downstream from the low pressure pump by the relief valve opening.

A control device is applied to a fuel supply system including a fuel pump that rotates an impeller in a housing and pumps fuel from a fuel tank and a fuel pipe in which fuel discharged from the fuel pump flows. The control device controls the fuel pump. The control device includes an execution device and a storage device that stores a program of a process which is performed by the execution device. In the control device, the execution device performs a coping process of increasing an amount of operation of the impeller when the impeller is deformed and interference with the housing is detected in comparison with a case in which the interference is not detected.

Unclogging group for unclogging a filter of a pumping group for pumping diesel to an internal combustion engine, the unclogging group comprising: —a metering unit comprising an electromagnetic head and a control valve for controlling the diesel flow; —a filter associated with the control valve made at least in part of metallic material; —a temperature sensor for measuring the ambient temperature; —a control unit coupled to the temperature sensor; —an electrical circuit controlled by the control unit for supplying electrical current to the filter; wherein the control unit is configured so once received the starting input of the pumping group it compares the temperature measured by the temperature sensor with a threshold value, and if the temperature measured by the temperature sensor is less than the threshold value the control unit commands a delay of the starling of the pumping group of a period wherein the control unit supplies electrical current to the electrical circuit connected to the filter.

A method for operating an internal combustion engine having an injection system which has a high-pressure accumulator, high pressure in the high-pressure accumulator being controlled via a suction throttle on the low-pressure side, acting as a first pressure control element in a first high-pressure control loop. During normal operation, a high-pressure disturbance variable is produced by a pressure regulating valve on the high-pressure side, acting as an additional pressure control element, via which fuel is re-directed from the high-pressure accumulator into a fuel reservoir, the at least one pressure regulating valve being controlled, during normal operation, based on a set volumetric flow rate for the fuel to be re-directed. A temporal development of the set volumetric rate is sensed and the set volumetric flow rate is filtered, a time constant for the filtering of the set volumetric flow rate being selected as a function of the sensed temporal development.

Embodiments of a gaseous or dual fuel electronic pressure regulation system (EPRS) for a multipoint fuel injection engine are described herein. Additionally, embodiments of a method for controlling the EPRS are provided. In particular, the EPRS employs an electronic pressure regulator (EPR) capable of accurately determining and controlling the mass flow of gaseous fuel into a fuel rail so as to avoid pressure droop and over- and under-pressurization of the gas admission valves (GAVs). By using the EPRS described above, mass flow is able to be distributed to the downstream manifold or engine cylinders very accurately, and the GAVs are able to be driven simultaneously in a pressure/pulse duration that is optimal for accurate and repeatable operation.

A fuel injection valve includes: a movable arrangement that is coupled to a movable core and a needle while a movable flow passage, which forms a part of a flow passage of the fuel injection valve, is formed at an inside of the movable arrangement; and a valve main body that receives the movable arrangement. The movable arrangement has: a first flow-restricting portion that reduces a cross-sectional area of a portion of the movable flow passage; and a second flow-restricting portion that is spaced away from the first flow-restricting portion and reduces a cross-sectional area of another portion of the movable flow passage to a cross-sectional area that is equal to or larger than a cross-sectional area of the first flow-restricting portion. A distance between the first flow-restricting portion and the second flow-restricting portion is larger than an equivalent diameter of the cross-sectional area of the second flow-restricting portion.

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.