A fuel pump assembly comprises a plunger arranged to reciprocate within a plunger bore via a drive shaft, to perform a pumping cycle comprising a pumping stroke and a return stroke, the pumping stroke comprising movement of the plunger from a bottom dead centre (BDC) position to a top dead centre (TDC) position, and the return stroke comprising movement of the plunger from the TDC position to the BDC position. The fuel pump assembly comprises a spring assembly including a return spring that is cooperable, at a first end, with a first member coupled to the plunger and movable at a first speed dependent on the speed of rotation of the drive shaft and, at a second end, with a second member which is movable at a damped speed relative to the first speed.

A fuel pump assembly comprises a plunger arranged to reciprocate within a plunger bore via a drive shaft, to perform a pumping cycle comprising a pumping stroke and a return stroke, the pumping stroke comprising movement of the plunger from a bottom dead centre (BDC) position to a top dead centre (TDC) position, and the return stroke comprising movement of the plunger from the TDC position to the BDC position. The fuel pump assembly comprises a spring assembly including a return spring that is cooperable, at a first end, with a first member coupled to the plunger and movable at a first speed dependent on the speed of rotation of the drive shaft and, at a second end, with a second member which is movable at a damped speed relative to the first speed.