This injection pump delivers high-pressure fuel to the engine's injectors at the precise timing required for combustion. It is a VP44 distributor-type pump, mounted on the engine and driven by the engine's timing gear train. The pump's internal rotary distributor meters fuel to each cylinder in sequence. A worn or failing pump causes hard starting, low power, or irregular engine running. This unit is a factory-remanufactured assembly; the original core is returned to the manufacturer under a deposit arrangement. On installation, ensure the pump timing is set to the engine specification and that all high-pressure fuel lines are torqued correctly.