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.

The invention relates to a method for controlling gaseous fuel pressure in an accumulator (12) of a fuel system (10) for a combustion engine (102) of a vehicle (100), wherein the method comprises the steps of: determining a nominal amount of gaseous fuel to be introduced into the accumulator; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve (24), which inlet valve is adapted to regulate input of gaseous fuel to the accumulator; and while the inlet valve is reduced or closed, performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber (104a-f) of the combustion engine by at least one injector (14a-f) of the fuel system, which at least one injection contributes to combustion in the combustion engine, thereby reducing pressure in the accumulator. The invention also relates to a corresponding fuel system (10).

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.

The present disclosure relates to a method for controlling pressure of an engine, including a controller structured to implement the method and an engine system including the controller. More specifically, the present disclosure relates to a method based on a mass balance analysis of a fuel system to determine how much mass needs to be pumped to maintain or achieve a certain pressure for the engine. In some embodiments, the method analyzes how much mass can be pumped by each pumping event based on current engine conditions. The analysis is performed over the smallest repeatable pump events and cylinder events cycle, or “subcycle,” based on the number of pump events and cylinder events for a given engine configuration.

A control apparatus of an internal combustion engine is provided. The internal combustion engine includes a port injection valve that injects fuel into an intake-air port, and a cylinder injection valve that injects fuel into a cylinder. The control apparatus includes an electronic control unit that controls the port injection valve and the cylinder injection valve such that when returning from a fuel cut, a value of a port increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a port injection, differs from a value of a cylinder increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a cylinder injection.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes determining a fuel injector error shape and applying a fueling correction to all injectors based on the fuel injector error shape.

A port fuel injection system includes a fuel pump configured to produce a flow of pressurized liquid fuel at a pressure between 10 and 50 bar. A fuel rail is connected to receive the flow of pressurized liquid fuel from the fuel pump, the fuel rail. A plurality of fuel injectors, including one fuel injector positioned in the intake port of each engine cylinder upstream of the intake valve for the engine cylinder are connected to receive pressurized fuel from the fuel rail. An engine control unit (ECU) receives signals from sensors on the internal combustion engine and is programmed to actuate the fuel injectors to deliver fuel to each engine cylinder over a full range of engine operating conditions. A port fuel injection system with high pressure and fast acting fuel injectors improves fuel delivery and performance over the full range of engine operating conditions.

A method for operating an engine fueling system to manage fuel in an accumulator supplying fuel to an engine including multiple cylinders comprising monitoring fuel load in the accumulator, determining that the engine is operating in a cylinder deactivation mode such as a skip-fire mode during which one or more fueling events to one or more of the cylinders is being skipped, and controlling a supply of fuel from a fuel pump to the accumulator during the cylinder deactivation mode operation. In embodiments, controlling the supply of fuel includes causing fuel to be supplied from the fuel pump to the accumulator if the monitored fuel load is less than or equal to a first fuel load, and causing fuel to be not supplied from the fuel pump to the accumulator if the monitored fuel load is greater than the first load value. Controlling the supply of fuel may comprise controlling the supply of fuel during each fueling event cycle of each deactivated cylinder.

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 apparatus for a fuel supply apparatus is used in an engine system. The engine system includes an engine including a fuel injection valve, and the fuel supply apparatus including a fuel pump configured to supply fuel in a fuel tank to a supply pipe connected to the fuel injection valve, and a relief valve provided in the supply pipe. The control apparatus for the fuel supply apparatus includes an executor configured to execute, when the fuel is supplied to the fuel tank, relief pressure control for driving the fuel pump to open the relief valve until a predetermined termination condition is satisfied.