Process for controlling the fuel addition to an I.C. engine comprises adding fuel to the engine depending on a first control signal and a second control signal. The first control signal controls the start and the end of the fuel addition and the second control signal controls the fuel pressure build up. The first control signal is produced from the signals which characterizes the amount of fuel to be injected, the start of the fuel addition and the fuel pressure at the start of the fuel addition. An Independent claim is also included for a device for controlling the fuel addition to an I.C. engine. Preferred Features: The duration of the first control signal is obtained from the signals, which characterizes the amount of fuel to be injected, the start of the fuel addition and the fuel pressure at the start of the fuel addition
