Abstract: A method for determining fuel volatility and consequently performing cold starting of an internal combustion engine; in the event of cold starting, the method provides for the determination of an enrichment percentage as a function of a stored value for fuel volatility; the determination of a predicted value for starting quality before performing starting; the starting of the engine using the previously determined enrichment percentage; the determination of a measured value for starting quality; the determination of a correction value of the stored value for fuel volatility as a function of the comparison between the measured value for starting quality and the predicted value for starting quality; and the updating of the stored value for fuel volatility by applying the correction value to said stored value, so consequently modifying the amount of enrichment in force.

Abstract: A method for determining fuel volatility and consequently performing cold starting of an internal combustion engine; in the event of cold starting, the method provides for the determination of an enrichment percentage as a function of a stored value for fuel volatility; the determination of a predicted value for starting quality before performing starting; the starting of the engine using the previously determined enrichment percentage; the determination of a measured value for starting quality; the determination of a correction value of the stored value for fuel volatility as a function of the comparison between the measured value for starting quality and the predicted value for starting quality; and the updating of the stored value for fuel volatility by applying the correction value to said stored value, so consequently modifying the amount of enrichment in force.

Abstract: The method comprises the steps consisting in assuming that the gain of at least one injector is equal to a theoretical gain or an updated gain, and in replacing each of at least one reference injection of injection control duration controlled by the engine control unit in application of a stored characteristic, with a multiple injection comprising a succession of at least two injections of injection control durations that are assumed to cause the same mass of fuel to be injected as by the replaced reference injection, in determining the fuel mass difference between the reference injection and the multiple injection, in deducing therefrom an error in determining the characteristic, and in modifying the gain and/or the offset of the linear zone of the initial characteristic or at least a table or mathematical relationship for the non-linear zone of said characteristic, so as to compensate the error, and storing the new characteristic as determined in this way.

Abstract: The method comprises the steps consisting in assuming that the gain of at least one injector is equal to a theoretical gain or an updated gain, and in replacing each of at least one reference injection of injection control duration controlled by the engine control unit in application of a stored characteristic, with a multiple injection comprising a succession of at least two injections of injection control durations that are assumed to cause the same mass of fuel to be injected as by the replaced reference injection, in determining the fuel mass difference between the reference injection and the multiple injection, in deducing therefrom an error in determining the characteristic, and in modifying the gain and/or the offset of the linear zone of the initial characteristic or at least a table or mathematical relationship for the non-linear zone of said characteristic, so as to compensate the error, and storing the new characteristic as determined in this way.

Abstract: The invention concerns a method for detecting clogging in a fuel filter, between a fuel pressure regulator imposing a pressure towards the internal combustion engine downstream of the filter and an electric motor pump compressing fuel coming from the tank towards the regulator through the filter which consists in: determining the fuel pressure at the pump output and by considering it as the fuel pressure at the filter intake; determining the fuel pressure at the filter outlet as being the pressure imposed by the regulator; determining the pressure drop of the filter from the difference between the filter input and output pressure levels, and by comparing at least a value based on the pressure drop with at least a reference value to deduce therefrom information concerning the clogging condition of the filter. The invention is applicable to preventive or predictive maintenance of fuel supply circuits in internal combustion engines.

Abstract: The invention concerns a pump with an electric motor pumping fule in a fuel tank and supplying a ramp of injectors aided by a fuel pressure regulator. The pump motor is controlled by a control unit for adjusting the pump output pressure, evaluated by a relationship between said pressure and at least a mean current of the pump motor, at an objective pressure level determined by the control unit and selected higher than the operating pressure of the regulator, such as a pressure-reducing valve, and whereof the pressure characteristic is known to the control unit. The invention is useful for supplying fuel to direct or indirect injection engines in motor vehicles.

Abstract: The control of the pressure in the high-pressure circuit (22) downstream from the pump (11) consists of controlling the solenoid valve (18) at the inlet of the pump (11) so that the fuel mass delivered by the pump (11) into the circuit (22) is equal to the algebraic sum of a fuel mass to be injected into the engine (1) and a fuel mass required to at least partially compensate a pressure difference between the fuel pressure measured by the sensor (4) in the circuit (22) and a target pressure desired by the control unit (5) in the circuit (22). Applies to pressure control for direct fuel injection into engines, particularly with externally supplied ignition.