A method according to the invention for checking the plausibility of the function of a pressure sensor in an injection system of an internal combustion engine includes acquiring a calibrated actuation profile, by which peak current values for opening at least one electrically actuatable injection valve are assigned to existing internal pressures. An existing internal pressure is measured in the form of an actual sensor pressure value by the pressure sensor. The method includes obtaining the electrical peak current value corresponding to the measured sensor pressure value from a calibrated actuation profile, such that the corresponding electrical peak current value acquired in this way is applied to the injection valve. Subsequently, an opening state of the injection valve is monitored in reaction to the applied electrical peak current value, and a functional state of the pressure sensor is assigned as a function of the opening state of the injection valve.

Disclosed is a method for detecting the direction of rotation of a crankshaft of an engine of a motor vehicle. The detection method includes in particular, when the crankshaft is in a second predetermined angular position between a low angular position and a high angular position of the crankshaft, a step of commanding the closure of a control valve for the intake of fuel into the high-pressure pump, a step of measuring a second pressure value in the high-pressure rail, and a step of detecting a nominal direction of rotation of the crankshaft if the second pressure value measured is greater than or equal to an expected pressure value or of detecting a reverse direction of rotation of the crankshaft if the second pressure value measured is less than the expected pressure value.

Methods and systems are provided for injector balancing without disabling a cam actuated high pressure fuel pump. In one example, one of a plurality of cam lobes of the pump is selectively and sequentially disabled while a group of injectors are concurrently operated to learn a pressure drop across each injector. The selection of the injectors is based on the identity and stroke timing of the disabled cam lobe.

Methods and systems are provided for controlling fuel injection to cylinders of an engine in a vehicle. In one example, a method comprises monitoring an electrical energy profile associated with a fuel injector that has been commanded to inject a predetermined amount of a fuel into an engine cylinder, inferring a fuel injection pressure based on the electrical energy profile, and controlling a subsequent fuel injection based on the inferred fuel injection pressure. In this way, fuel injection may be controlled without relying on a pressure sensor in a fuel rail that supplies fuel to the fuel injector, under conditions where the fuel rail does not include the pressure sensor or where the pressure sensor is degraded.

A fuel injection control device according to an embodiment is a device for controlling fuel injection performed by a fuel injection device disposed in a cylinder of a two-stroke engine, comprising: a scavenging and exhaust gas state quantity acquisition part configured to acquire a parameter related to a state quantity of scavenging and exhaust gas in the cylinder; a swirl momentum calculation part configured to calculate a momentum of swirl generated in the cylinder on the basis of the parameter; and a fuel injection pressure calculation part configured to calculate an injection pressure of fuel from the fuel injection device corresponding to the momentum of swirl calculated by the swirl momentum calculation part.

Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

A method for operating a speed-controlled fluid pump includes: providing an electrical control current for the fluid pump; providing a maximum value for the electrical control current, which maximum value corresponds to a maximum permissible pressure at an outlet side of the fluid pump; providing a threshold value for the control current, the threshold value corresponding to a further maximum permissible pressure at the outlet side of the fluid pump and is predefined in dependence upon at least one boundary condition, the threshold value being less than the maximum value for the electrical control current; and controlling the fluid pump with not more than the threshold value for the control current, if it has been determined that the at least one boundary condition holds, so as to limit the pressure at the outlet side of the fluid pump to a value provided for the at least one boundary condition.

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.

Methods and systems are provided for operating a lift pump of an engine fuel system. In one example, a method may comprise predicting when a fuel rail pressure will decrease below a threshold assuming that a lift pump remains off. The method may further comprise powering on the lift pump before the fuel rail pressure decreases below to the threshold to prevent fuel rail pressure from decreasing below the threshold.