A fuel pump for conveying fuel includes a conveying unit having a cylinder, a plunger received in the cylinder, a pump spring received in the cylinder, an inner sleeve connected to the plunger, an outer sleeve in contact with the pump spring and in contact with a roller of a cam mechanism, and a locking bolt configured to detachably connect the inner and outer sleeves.

A fuel pump manifold pressure control system may be effective to provide a compact and more effective fuel pump mechanism for compression ignition engines, such as diesel and some natural gas engines. The fuel pump manifold pressure control system includes a fuel pump manifold, at least one fuel injection accumulator adapted for supplying pressurized fuel to at least one fuel injector, a pressure control valve, a pressure sensor, and a pressure relief valve, all contained within a compact fuel pump housing. The pressure control valve and pressure sensor are each adapted for signal communication with electronic controller, and for fuel communication with the fuel pump manifold. The pressure relief valve is adapted for fuel communication with the fuel pump manifold. Each of the control valve, sensor, and relief valve are fixedly mounted to and internally contained within the housing.

A fuel delivery system for a direct injection internal combustion engine having two fuel rails and a plurality of fuel injectors attached to and fluidly connected with each fuel rail. A first fuel pump has its output connected with the first fuel rail while a second fuel pump has its output connected with the second fuel rail. A crossover pipe fluidly connects the outlets of both the first and second pumps. Both the first pump and the second pump each have an intake stroke and a pumping stroke. Furthermore, the intake stroke of the first pump coincides with the pumping stroke of the second pump and vice versa.