A method for the self-learning of the variation of a nominal functioning feature of a high pressure pump in an internal combustion engine, which pump feeds fuel to a common rail and is controlled by a solenoid valve depending on an objective pressure inside the common rail and by using the nominal functioning feature which provides a delivery of fuel; in cut-off conditions of the engine, the method includes determining the value of the pressure leaks due to blow-by in the common rail; measuring the real pressure of the fuel inside the common rail; actuating the high pressure pump by controlling the solenoid valve with a predetermined closing angle; measuring the real pressure of the fuel inside the common rail again; determining a pressure deviation between the real pressure and an expected pressure of the fuel, and correcting the nominal functioning feature according to this deviation.