This mechanical feed pump draws fuel from the tank and delivers it to the injection system at the required pressure. It is mounted on the engine block and is driven by the engine's camshaft or an intermediate gear. The pump's internal diaphragm or piston creates the suction and pressure needed to supply the injection pump. A failing pump results in hard starting, loss of power, or erratic engine running. This component is built to the original manufacturer's specifications, ensuring the correct displacement and pressure characteristics for the host engine. When replacing, ensure the gasket surface is clean and the mounting bolts are torqued to specification.