Method for controlling a fuel injector according to a control law which is differentiated as a function of injection time

A method for controlling a fuel injector (1) provided with an electrically operated electromagnetic actuator (5) in such a manner as to open the injector (1) for a determined injection time (Tj); the method providing that the injector (1) be operated with a first current waveform (A) if the injection time (Tj) is greater than a predetermined threshold value (Ts), and that the injector (1) be operated with a second current waveform (B) if the injection time (Tj) is less than the predetermined threshold value (Ts); both the current waveforms (A, B) have an identical initial portion, during which the current (i(t)) passing through the injector (1) is caused to rise until it reaches a peak value (Ip), which is maintained by cyclic switching of the voltage (v(t)) applied to the injector (1) between two different values (0, Vc).