A method for regulating a fuel delivery system without a pressure sensor. The fuel delivery system has a fuel delivery pump, an electric motor, and an evaluation unit. The fuel delivery pump is driven by the electric motor, which is actuated using control variables such that a prespecifiable fuel delivery is achieved. At least two different submethods are executed for ascertaining control variables, which are ascertained in the respective submethod and are supplied to an evaluation unit. The control variables are evaluated regarding their plausibility in the evaluation unit and the electric motor is actuated based on the ascertained control variables from only one or a plurality of submethods.

A method for regulating a fuel delivery system of an internal combustion engine in a motor vehicle having a fuel delivery pump for supplying the internal combustion engine with fuel, the fuel delivery pump having a pump mechanism driveable by an electric motor actuable by a control signal, and a pressure-sensor-free pressure monitor being provided in the fuel delivery system, includes: predefining a target rotational speed for the electric motor based on the control signal; predefining an upper rotational speed limit and/or a lower rotational speed limit for the target rotational speed, wherein the upper rotational speed limit depends on the maximum fuel requirement of the internal combustion engine, and the lower rotational speed limit depends on the minimum fuel requirement of the internal combustion engine; and determining the target rotational speed by a pressure-sensor-free calculation method.

Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Methods and systems are provided for reducing fueling errors resulting from pressure pulsations in a port injection fuel rail. The pressure pulsations result from pressure pulsations generated in a high pressure fuel pump delivering fuel to both the port injection fuel rail and a direct injection fuel rail. A center of a port injection fuel pulse is positioned on an average pressure-crossing of the pressure pulsations so as to cancel out the effect of the over-average and under-average pressure pulsations.

A method for measuring pressure of a gaseous fuel compressed in a feed system of an engine equipping a motor vehicle, by a pressure measuring device having an infrared quality sensor and an electronic control unit, the measuring method being characterized in that it consists in determining a corrected absorbance value of the fuel based on absorbance measurements performed by infrared analysis, at preset wavelengths, and in comparing the value to a nominal absorbance value, determined beforehand based on absorbance measurements performed at a nominal pressure after a pressure stabilization phase of the fuel and at the same said wavelengths, in order to determine the fuel pressure.

A controller for an internal combustion engine is configured to control the fuel injection valve so that the fuel injection valve selectively performs partial lift injection, which does not open a valve member at a fully open position, and full lift injection, which opens the valve member at the fully open position. The internal combustion engine includes the fuel injection valve and a fuel supply system. The controller includes an energizing time setting unit, a fuel pressure calculation unit, and a smoothening process unit. The energizing time setting unit is configured to set an energizing time for the full lift injection based on graded fuel pressure calculated by the smoothening process unit and set an energizing time for the partial lift injection based on fuel pressure calculated by the fuel pressure calculation unit.

A method of controlling the fuel rail pressure of a fuel injection system of an internal combustion engine is disclosed. A failure condition of a fuel rail pressure sensor is detected. A fuel rail pressure target value and an injector fuel output target value are determined on the basis of an internal combustion engine operating condition. A fuel pump output target value to be supplied into the fuel rail is determined. The fuel pump is driven in order to provide the fuel pump output target value. The fuel pump output target value is determined on the basis of the injector fuel output target value, and the fuel injector is energized for an energizing time target value determined on the basis of the fuel rail pressure target value and the injector fuel output target value.

A method for controlling a fuel delivery system of an internal combustion engine, having a fuel delivery pump that is driven by an electric motor. The pressure that prevails in the fuel delivery system is determined by a volume difference between the fuel quantity delivered by the fuel delivery pump and the fuel requirement of the internal combustion engine and/or of the fuel delivery system.

A method is described for operating an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine, having a high-pressure reservoir and a high-pressure pump, of a motor vehicle. The electric fuel pump is operated at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with a minimum value for a control application variable for the electric fuel pump.

A method and to a device for operating a pressure reservoir, where during a compression phase in a pump chamber, a pump periodically increases the pressure of a fluid located therein, and by means of a discharge valve controlled by differential pressure fluid under high pressure is allowed to be introduced from the pump chamber into the pressure reservoir. During a decompression phase following a compression phase, fluid from a fluid reservoir is introduced into the pump chamber by means of a controllable intake valve. In order to be able also to operate the pressure reservoir without a high pressure measurement directly in the pressure reservoir, the fluid pressure in the pressure reservoir is ascertained by means of a pressure determination in the pump chamber. The pressure determination takes place indirectly, monitoring of the intake valve in the decompression phase.