METHOD TO CONTROL A HIGH-PRESSURE FUEL PUMP FOR A DIRECT INJECTION SYSTEM

The invention relates to a method to control a fuel pump (4) for a direct injection system of a heat engine (1) provided with a common rail (3) comprising the steps of determining a minimum threshold (Q) based on the pressure (P) in the common rail (3) and on the speed (n) of the heat engine (1), on the temperature (T) of the high-pressure pump (4) and on the inlet pressure (P) of the high-pressure pump (4); calculating the objective fuel flow rate (M) to be fed by the high-pressure pump (4) to the common rail (3) instant by instant in order to have the desired pressure value (P) inside the common rail (3); comparing the objective fuel flow rate (M) with the minimum threshold (Q); and controlling the high-pressure pump (4) based on the comparison between the objective fuel flow rate (M) and the minimum threshold (Q) .