Various embodiments include a high-pressure fuel pump for a fuel injection system comprising: a housing defining a housing bore with a pressure chamber in a first end region and a leakage chamber in a second end region; a pump piston, during operation of the high-pressure fuel pump moved in translation between the pressure chamber and the leakage chamber along an axis; wherein the leakage chamber includes a leakage collecting region and an equalizing region arranged in circular annular fashion around the pump piston guiding section and extending parallel to the axis from the leakage collecting region toward the pressure chamber; and a low-pressure damper arranged in the equalizing region, the low-pressure damper comprising an annular piston damper and an annular piston guided to move along the axis within an annular bushing.

A fuel injector includes an injector body, and a stack within the injector body, and having a nozzle supply passage therein. The stack includes a solenoid assembly having a solenoid housing piece with a fuel bore formed therein that includes a segment of the nozzle supply passage. The solenoid housing piece includes a solenoid housing material in a base state, and a solenoid housing material in a residual compressive stressed state, with the fuel bore being formed by the solenoid housing material in the residual compressive stressed state. Residual stresses may be imparted by ballizing, nitriding, carburizing, autofrettage, or still another technique.

A fuel injector includes an injector body, and a plunger movable within a plunger cavity in the injector body. The fuel injector also includes a spill valve positioned at least partially within a main fuel passage, a fill passage forming a fluid connection between the plunger cavity and the main fuel passage, and a cross passage forming a second fluid connection between the plunger cavity and the main fuel passage. The fuel injector also includes a metering edge within the plunger cavity and positioned such that the plunger passes the metering edge during pumping to the plunger for valvetrain noise suppression. A metering slot may be formed in the injector body or the plunger.

A shuttle valve for a control valve coupled to an electronic fuel injector is disclosed. The shuttle valve may include a shuttle valve first end including an armature attachment portion operably coupled to an armature of the control valve and a shuttle valve second end opposite the shuttle valve first end defining a sealing portion of the control valve including an annular sealing surface. A valve guide portion may extend axially along a portion of the shuttle valve between the first and second ends. Furthermore, an engagement surface portion may be defined along the valve guide portion that is slidably engaged with a valve bore. Moreover, the shuttle valve may include a non-engagement surface portion defined along the valve guide portion, wherein the non-engagement surface is a non-continuous surface around a circumference of the valve guide portion and wherein the non-engagement surface is interspersed between portions of the engagement surface.

A fuel injector includes an injector body, and a plunger movable within a plunger cavity in the injector body. The fuel injector also includes a spill valve positioned at least partially within a main fuel passage, a fill passage forming a fluid connection between the plunger cavity and the main fuel passage, and a cross passage forming a second fluid connection between the plunger cavity and the main fuel passage. The fuel injector also includes a metering edge within the plunger cavity and positioned such that the plunger passes the metering edge during pumping to the plunger for valvetrain noise suppression. A metering slot may be formed in the injector body or the plunger.

A driveshaft assembly, for example in an Electronic Unit Injector, Unit Injector or Electronic Unit Pump testing machine, wherein an indexing arrangement, such as complementary external and internal splines, enables a cam to be mounted on a shaft at a number of discreet positions, each providing a different offset of a central axis of the base cylinder section from a central axis of the shaft, each position providing a different maximum lift value of a plunger in contact with the cam, directly or via a rocker arm.

A fuel system is disclosed for use with an engine, including a fuel injector assembly fluidly coupled with a low-pressure fuel conduit, an accumulator, and a cap within an opening in the accumulator. The fuel injector assembly may be structured to draw in low-pressure fuel, pressurize the fuel, and store the pressurized fuel in the accumulator for injection to a combustion chamber. The cap has a pressure sensor and a pressure relief valve therein, and drains fuel leaked past fluid seals between the cap and each of the pressure sensor, the pressure relief valve, and the accumulator by way of a common drain line.

A method of testing a unit pump system performance is disclosed. In one embodiment of the present disclosure, the method of testing a unit pump system performance determines if mechanical and/or electrical stability of a control valve of the unit pump system are achieved before measuring an output injection volume variation.

A method of improving fuel delivery in an engine having one or more cylinders that are over-fueled related to other cylinders, such as a D-EGR engine. The fueling system uses a mechanical fuel pump, which is cam-driven. The cam has lobes corresponding to the desired displacement for each cylinder. The lobe corresponding to the over-fueled cylinder is shaped differently, such that the filling stroke of the pump is increased.

A dual fuel system for an internal combustion engine includes a first fuel supply of a liquid pilot fuel, a primary fuel supply of a liquid primary fuel, and a dual fuel injector. The dual fuel injector includes a spill valve fluidly connected with a plunger cavity and movable to control a start of injection and an end of injection, and an admission valve. The admission valve is movable to admit a pilot fuel into the fuel injector, such that the pilot fuel is conveyed through an outlet check to form, within a primary fuel passage fluidly connected to the plunger cavity, a segmented fuel charge of leading pilot fuel and trailing primary fuel by displacing some of the primary fuel. The liquid pilot fuel may be a higher cetane/lower octane liquid fuel, and the primary fuel may be a lower cetane/higher octane liquid fuel.