A method for determining a quantity of fuel flowing through a fuel injector, the fuel injector having an electric heating device for heating the fuel and a temperature-measuring device for measuring a temperature of the heated fuel, the method comprising:
- applying a predetermined electrical heating power to the electric heating device;
- measuring an increase in the temperature of the fuel caused by the heating power;
- and
- determining the quantity of fuel flowing through the fuel injector from the electrical heating power applied to the electric heating device and the measured increase in the temperature of the fuel.