Method of controlling a non-return fuel supply system for an internal combustion engine and a supply system for working the said method

A non-return fuel supply system for an internal combustion engine operating with at least one cylinder and comprising: at least one intake manifold connected to the cylinder, at least one injector for injecting fuel into the intake manifold, a fuel tank, a pump substantially positioned in the tank in order to deliver fuel to the injector, and a control station comprising a first calculating unit adapted, for each injector, to calculate the value of the average pressure difference between the ends of the injector during each injection phase, and a second calculating unit connected to the first calculating unit and adapted, for each injector, to calculate the average value of the flow rate of the injector during each injection phase on the basis of the value of the average pressure difference between the ends of the injector during the injection phase.\!