A fuel injection system includes a first high pressure fuel source, a return channel connected to a second low pressure fuel source, a residual pressure regulator having an inlet and an outlet connected to the return channel, and a fuel injector having a control valve arrangement comprising an inlet, an outlet and a return port, a fuel injection nozzle having an outlet chamber, an injection outlet, and a needle member in the outlet chamber. The needle member is biased to a closed position to block fluid communication between the outlet chamber and the injection outlet, and to open fluid communication by a pressure in the outlet chamber. The residual pressure regulator is connected to a spill valve to regulate pressure to a residual pressure higher than the pressure in the return channel and lower than the pressure of the first fuel source.

A fuel injector includes an injector body which accommodates a pole piece of a solenoid actuator. A top portion of the injector body includes a cylindrically formed generally open-ended recessed portion. The recessed portions accommodates a generally cylindrical pole piece, wherein the pole piece includes a bore located along a central axis to provide a fuel flow path. The top portion of the pole piece includes a cylindrically formed recess so as to form a sleeve or lip portion.

Fueling systems and methods are disclosed. Various fueling systems may comprise a single fuel pump configured to supply fuel to a first fuel rail at a first fuel pressure along a first fuel circuit and configured to supply fuel to a second fuel rail at a second fuel pressure along a second fuel circuit, wherein the first fuel rail and second fuel rail are arranged in parallel, and the first fuel circuit is independent of the second fuel circuit.

An electrically actuated control valve has three mouths and three operating positions, in which the three mouths includes a first mouth for inlet of a working fluid, and a second mouth and a third mouth for outlet of the working fluid. The three operating positions include a first operating position in which a passage of fluid from the first mouth to the second mouth and the third mouth is enabled, a second operating position in which a passage of fluid from the first mouth to only one of said second and third mouths is enabled, and a third operating position in which the passage of fluid from the first to the second mouth and the third mouth is disabled. The control valve includes an electric or electromagnetic actuator for controlling the passage of fluid from the first mouth to the second and third mouths providing the aforesaid three operating positions.

An ECU calculates peak-current arrival time (time elapsed before a detected current arrives at a target peak current), and calculates predetermined-current arrival difference time (time elapsed before the detected current becomes lower than a predetermined current after exceeding the predetermined current). The ECU uses a beforehand stored relationship between the predetermined-current arrival difference time and defined peak-current arrival time to calculate the defined peak-current arrival time corresponding to the latest predetermined-current arrival difference time. The ECU uses such defined peak-current arrival time to compare the latest peak-current arrival time with the defined peak-current arrival time (for example, calculates a difference between the peak-current arrival time and the defined peak-current arrival time), and thus determines a shift in detected current of a current detection circuit.

A system includes one or more processors that are configured to obtain a measured fuel consumption rate for an internal combustion engine while the engine is operating at a predetermined operating condition to perform a mission. The one or more processors are also configured to compare the measured fuel consumption rate with an expected fuel consumption rate for the predetermined operating condition. Further, the one or more processors are configured to determine whether an injector flow limiter is in a latched condition based on the measured fuel consumption rate compared with the expected fuel consumption rate. Also, the one or more processors are configured to perform a responsive action responsive to determining that the injector flow limiter is in the latched condition.

A fuel injector includes an injector body which accommodates a pole piece of a solenoid actuator. A top portion of the injector body includes a cylindrically formed generally open-ended recessed portion. The recessed portions accommodates a generally cylindrical pole piece, wherein the pole piece includes a bore located along a central axis to provide a fuel flow path. The top portion of the pole piece includes a cylindrically formed recess so as to form a sleeve or lip portion.

The present disclosure relates to a fuel injector for injecting fuel into a combustion engine. It may comprise a valve with a movable needle, two springs pushing the needle toward the closed position, and an actuator for opening the valve. The needle may be in a fuel reservoir of a valve body. The actuator may supply pressurized fuel to the fuel reservoir so that the fuel pressure forces the needle away from the closed position against the spring force of the first spring or the first and second springs, respectively. There may be play between the second spring and the needle when the needle is in the closed position.

A system includes one or more processors that are configured to obtain a measured fuel consumption rate for an internal combustion engine while the engine is operating at a predetermined operating condition to perform a mission. The one or more processors are also configured to compare the measured fuel consumption rate with an expected fuel consumption rate for the predetermined operating condition. Further, the one or more processors are configured to determine whether an injector flow limiter is in a latched condition based on the measured fuel consumption rate compared with the expected fuel consumption rate. Also, the one or more processors are configured to perform a responsive action responsive to determining that the injector flow limiter is in the latched condition.

A fuel injector includes a nozzle having at least one nozzle outlet. A valve needle is moveable with respect to a valve needle seating through a range of movement between a closed position and an open position to control fuel delivery through the at least one nozzle outlet. The movement of the nozzle needle is controlled by fuel pressure within a control chamber. The injector has first and second nozzle control valves for controlling fuel flow into and out of the control chamber to pressurise and depressurise the control chamber, respectively. The first nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain or to place the control chamber in fluid communication with a high pressure supply line. The second nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain.