Fuel injection system

Fuel injection system having a piezoelectric element for controlling the amount of injected fuel into a combustion engine, wherein electric power for driving the piezoelectric element is supplied by an electric power source, and wherein the fuel injection system comprises a controllable voltage converter disposed between the piezoelectric element and the electric power source and a control unit for adjusting a current between the electric power source and the controllable voltage converter to a value between 0 ampere and a maximum current.