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.

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.

Provided is a fuel injection device for engines, configured using a technique which can extend service life while good responsiveness is maintained. This fuel injection device for engines is provided with: a control rack supported so as to be slidable in an axial direction and configured so that the amount of fuel delivered under pressure by a fuel pumping mechanism can be adjusted by changing the sliding position of the control rack in the axial direction; an actuator which can move forward and backward an operation section; and a link lever which is supported in a rockable manner by a support shaft and which rocks as the operation section of the actuator moves forward and backward, thereby sliding the control rack. The fuel injection device for engines is further provided with an actuator-side connection section for connecting the operation section of the actuator to the link lever. The actuator-side connection section is disposed coaxially with the operation section of the actuator.

Provided is a fuel injection device for engines, configured using a technique which can extend service life while good responsiveness is maintained. This fuel injection device for engines is provided with: a control rack supported so as to be slidable in an axial direction and configured so that the amount of fuel delivered under pressure by a fuel pumping mechanism can be adjusted by changing the sliding position of the control rack in the axial direction; an actuator which can move forward and backward an operation section; and a link lever which is supported in a rockable manner by a support shaft and which rocks as the operation section of the actuator moves forward and backward, thereby sliding the control rack . The fuel injection device for engines is further provided with an actuator-side connection section for connecting the operation section of the actuator to the link lever. The actuator-side connection section is disposed coaxially with the operation section of the actuator.

A technology that can extend the life of a fuel injection device of an engine while maintaining its good responsiveness is provided. A fuel injection device 100 for an engine includes: a control rack 55 supported to be slidable in an axial direction and capable of adjusting of a fuel pressure-feed amount of a fuel pressure-feed mechanism unit 51, based on its slide-position relative to the axial direction; an actuator 40 capable of reciprocating its operating unit 41; and a link lever 20 swingably supported by a pivot shaft member 25 and configured to swing in association with reciprocation of the operating unit 41 of the actuator 40 thereby causing the control rack 55 to slide, wherein the fuel injection device includes an actuator-side connecting part 20A connecting an operating unit 41 of the actuator 40 to the link lever 20, and the actuator-side connecting part 20A is positioned on the same axis as the operating unit 41 of the actuator 40.

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 technology that can extend the life of a fuel injection device of an engine while maintaining its good responsiveness is provided. A fuel injection device 100 for an engine includes: a control rack 55 supported to be slidable in an axial direction and capable of adjusting of a fuel pressure-feed amount of a fuel pressure-feed mechanism unit 51, based on its slide-position relative to the axial direction; an actuator 40 capable of reciprocating its operating unit 41; and a link lever 20 swingably supported by a pivot shaft member 25 and configured to swing in association with reciprocation of the operating unit 41 of the actuator 40 thereby causing the control rack 55 to slide, wherein the fuel injection device includes an actuator-side connecting part 20A connecting an operating unit 41 of the actuator 40 to the link lever 20, and the actuator-side connecting part 20A is positioned on the same axis as the operating unit 41 of the actuator 40.

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 fuel injection pump (100) provided in a diesel engine, including: an electromagnetic spill valve (20) configured to adjust a fuel injection amount by releasing a pressurized fuel with opening/closing of a spill valve body (23); and an ECU (Engine Control Unit, 50) configured to form a current waveform of drive current of the electromagnetic spill valve (20). The ECU (50), during the warm state, detects a valve-close timing of the electromagnetic spill valve (20), forms an optimum current waveform of drive current based on the detected valve-close timing, and applies drive current with thus formed optimum current waveform to the electromagnetic spill valve (20), whereas, during the cold state, the ECU (50) applies only drive current with a pre-set current waveform to the electromagnetic spill valve (20).

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.