Systems and methods are provided for operating a port fuel and direct injection fuel system of a rolling variable displacement engine (rVDE). In one example, a method may include selecting between controlling a lift pump of the fuel system to output fuel at a mechanically limited pressure and controlling the lift pump to output fuel at a pressure lower than the mechanically limited pressure based on whether port fuel injection is used. In this way, the lift pump may be controlled without feedback from a pressure sensor, reducing system costs, while electrical power consumption increases due to operating the lift pump to output fuel at the mechanically limited pressure are minimized due to the rVDE technology, which reduces port fuel injection usage.

A common rail fuel injection device includes first and second flow rate regulating valves for regulating a delivery volume of a pressurized fuel feed pump that feeds pressurized fuel to a common rail, a pressure reducing valve for reducing a common rail pressure, and a control device. The control device for the common rail fuel injection device includes a first drive controlling unit that controls a first electromagnetic driving unit for the second flow rate regulating valve and a second electromagnetic driving unit for the pressure reducing valve, and a second drive controlling unit that controls a third electromagnetic driving unit for the first flow rate regulating valve. The first drive controlling unit prohibits a drive instruction from being sent to the second flow rate regulating valve when the first drive controlling unit sends a drive instruction to the pressure reducing valve.

A high pressure pump for complex injection engines is provided. A body of the high pressure pump includes a first flow path that transports the low pressure fuel flowing in through the low pressure fuel inlet and a low pressure fuel storage chamber that is disposed in a lower portion of the body to store the low pressure fuel transported from the first flow path. A second flow path transports the low pressure fuel stored in the low pressure fuel storage chamber and a flow control valve is disposed over the low pressure fuel storage chamber to discharge the low pressure fuel, transported through the second flow path, to the pressure unit or the damper disposed in an upper portion of the body based on an opening or closing operation. A low pressure fuel outlet discharges the low pressure fuel, transported through the damper, to a low pressure fuel rail.

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.

When a rotational speed of an engine is higher than a predetermined rotational speed, a low-pressure fuel injection valve is controlled through the use of a fuel injection time based on an estimated fuel pressure in a low pressure supply pipe and a target fuel injection amount. When the rotational speed of the engine is equal to or lower than the predetermined rotational speed, the low-pressure fuel injection valve is controlled through the use of a fuel injection time based on a detected fuel pressure input from the fuel pressure sensor from the issuance of a command to activate energization of a solenoid to the start of energization of the solenoid and a target fuel injection amount.

A common-rail fuel injection device for an internal combustion engine, including fuel injection valves each having two fuel supply ports, is known as a fuel injection device for suppressing temporary decrease of a fuel pressure immediately after the end of fuel injection from the fuel injection valve. Even in this fuel injection device, the fuel injection pressure may fluctuate immediately after the end of fuel injection, thereby causing changes of amount and particle diameter of injected fuel. A common rail is connected to one fuel supply port of the fuel injection valve, whereas another fuel injection valve, which is non-contiguous in the order of combustions, is connected to the other fuel supply port by an injection-valve connection pipe.

A modular system for injecting fuel into an engine comprises a fuel rail coupled to the engine. A plurality of connection members are coupled to the fuel rail, and each of the plurality of connection members is configured to receive fuel from the fuel rail. The fuel is directed to a plurality of fuel injectors, and the plurality of fuel injectors are configured to direct fuel to a plurality of cylinders. A plurality of outer fuel lines are coupled to the plurality of connection members, and the plurality of outer fuel lines are arranged in a single configuration. The single configuration allows the fuel rail to be coupled to a plurality of engine configurations while maintaining the plurality of outer fuel lines arranged in the single configuration.

Methods and systems are provided for controlling a low pressure pump in port fuel direct injection (PFDI) engines. One method includes, when operating a high pressure pump in a default pressure mode, pulsing the low pressure pump when pressure in a high pressure fuel rail decreases below a threshold. The method further includes, when operating the high pressure pump in a variable pressure mode, pulsing the low pressure pump based on presence of fuel vapor at an inlet of the high pressure pump.

A distributor apparatus of a common rail system for an internal combustion engine. The distributor apparatus is designed with at least one distributor device having a high-pressure line for fuel and a plurality of feed lines branching off from the high-pressure line within the distributor device. Each feed line leads to an individual accumulator and an injector. The feed line is associated with a restriction device and a discharge bore, which is designed to cooperate with a pressure-measuring device and which is arranged downstream of the restriction device, such that the restriction device is arranged in the feed line and the discharge bore, arranged in the distributor device, is connected to the feed line downstream of the restriction device.

When a rotational speed of an engine is higher than a predetermined rotational speed, a low-pressure fuel injection valve is controlled through the use of a fuel injection time based on an estimated fuel pressure in a low pressure supply pipe and a target fuel injection amount. When the rotational speed of the engine is equal to or lower than the predetermined rotational speed, the low-pressure fuel injection valve is controlled through the use of a fuel injection time based on a detected fuel pressure input from the fuel pressure sensor from the issuance of a command to activate energization of a solenoid to the start of energization of the solenoid and a target fuel injection amount.