Abstract: A method for monitoring a fuel pressure in a fuel injection system of an internal combustion engine. A setpoint fuel pressure is initially set in the fuel injection system. Next, a first fuel injection and a subsequent second fuel injection are executed at a time interval shorter than a decay time of a pressure wave in the fuel injection system, triggerable by the first fuel injection. In an additional step, a monitored fuel injection quantity, which is injected via the second fuel injection, is ascertained. An action is executed if the monitored fuel injection quantity differs from a setpoint fuel injection quantity, which is predefinable for the setpoint fuel pressure, by more than a limiting value. The invention also relates to a computer program product for executing the method and to a device for monitoring a fuel pressure in a fuel injection system of an internal combustion engine.

Abstract: A method for assessing a method of functioning of a fuel injector in response to the application of a control voltage to at least one actuator of the fuel injector, including the steps of applying the control voltage to the at least one actuator of the fuel injector for a no-torque-generating injection into an engine, determining a fuel content in an exhaust tract disposed at an engine, comparing the determined fuel content with a specified comparison value, and assessing the method of functioning of the fuel injector based on the comparison result. Furthermore, also described is an evaluation device for assessing a method of functioning of a fuel injector in response to the application of a control voltage.

Abstract: Described is a method for operating an internal combustion engine (1), in which method at least one parameter of the exhaust gas flowing in an exhaust-gas duct (10) is detected by at least one exhaust-gas probe (30; 32), wherein the internal combustion engine (1) is at least temporarily turned over by a starting device (3), during which an injection and combustion of fuel does not take place, and during and/or after which the exhaust-gas probe (30; 32) is adjusted.

Abstract: A method for operating an internal combustion engine, in which fuel is injected into a combustion chamber of the internal combustion engine with the aid of an injector, a variable which characterizes a slope of a straight line or of a curve which has at least some sections in the shape of a straight line, being ascertained, the straight line or straight line-shaped curve linking activation times of the injector to the appropriate difference values, and a difference value being formed by the difference between an instantaneous closing point in time and a reference closing point in time or between an instantaneous injection quantity and a reference injection quantity, and a measure for a coking of the injector being ascertained from the ascertained variable.

Abstract: A method for monitoring a fuel pressure in a fuel injection system of an internal combustion engine. A setpoint fuel pressure is initially set in the fuel injection system. Next, a first fuel injection and a subsequent second fuel injection are executed at a time interval shorter than a decay time of a pressure wave in the fuel injection system, triggerable by the first fuel injection. In an additional step, a monitored fuel injection quantity, which is injected via the second fuel injection, is ascertained. An action is executed if the monitored fuel injection quantity differs from a setpoint fuel injection quantity, which is predefinable for the setpoint fuel pressure, by more than a limiting value. The invention also relates to a computer program product for executing the method and to a device for monitoring a fuel pressure in a fuel injection system of an internal combustion engine.

Abstract: A method for the determination of a fuel mass of a pre-injection injected into at least one combustion chamber of an internal combustion engine by means of at least one injection under high pressure is characterized in that a corrective variable is determined for the pre-injection by means of a comparison between a measure for the actual amount of injected fuel of at least one test post-injection carried out for a predetermined target amount of a desired pre-injection due to a measure, and the measure for the target amount.

Abstract: A method for operation of an internal combustion engine, comprising an exhaust treatment device in the exhaust system thereof, with application of a reagent under given operating conditions of the internal combustion engine and/or the exhaust treatment device and a device for carrying out the method are disclosed, wherein a correction parameter is determined for a reagent signal, describing the amount of reagent to be introduced into the exhaust system and the correction parameter is determined by means of a comparison of a measure of the actual amount of the reagent in the exhaust system, which should be introduced based on a measure of a pre-determined set amount and the measure of the set amount. The above method permits a particularly exact maintenance of the amount of reagent introduced into the exhaust system in accordance with the pre-determined measure for the set amount.

Abstract: Described is a method for operating an internal combustion engine (1), in which method at least one parameter of the exhaust gas flowing in an exhaust-gas duct (10) is detected by at least one exhaust-gas probe (30; 32), wherein the internal combustion engine (1) is at least temporarily turned over by a starting device (3), during which an injection and combustion of fuel does not take place, and during and/or after which the exhaust-gas probe (30; 32) is adjusted.

Abstract: In a fuel system of an internal combustion engine, the fuel quantity injected into a combustion chamber is a function of an activation period, during which a fuel injection device is activated. A pressure sensor detects the pressure in the fuel rail and provides a signal. The pressure in the fuel rail may be regulated to a setpoint pressure using a setting unit and employing the signal provided by the pressure sensor.

Abstract: A method for the determination of a fuel mass of a pre-injection injected into at least one combustion chamber of an internal combustion engine by means of at least one injection under high pressure is characterized in that a corrective variable is determined for the pre-injection by means of a comparison between a measure for the actual amount of injected fuel of at least one test post-injection carried out for a predetermined target amount of a desired pre-injection due to a measure, and the measure for the target amount.

Abstract: A method for assessing a method of functioning of a fuel injector in response to the application of a control voltage to at least one actuator of the fuel injector, including the steps of applying the control voltage to the at least one actuator of the fuel injector for a no-torque-generating injection into an engine, determining a fuel content in an exhaust tract disposed at an engine, comparing the determined fuel content with a specified comparison value, and assessing the method of functioning of the fuel injector based on the comparison result. Furthermore, also described is an evaluation device for assessing a method of functioning of a fuel injector in response to the application of a control voltage.

Abstract: In a fuel system of an internal combustion engine, the fuel quantity injected into a combustion chamber is a function of an activation period, during which a fuel injection device is activated. A pressure sensor detects the pressure in the fuel rail and provides a signal. The pressure in the fuel rail may be regulated to a setpoint pressure using a setting unit and employing the signal provided by the pressure sensor.

Abstract: A method for operation of an internal combustion engine, comprising an exhaust treatment device in the exhaust system thereof, with application of a reagent under given operating conditions of the internal combustion engine and/or the exhaust treatment device and a device for carrying out the method are disclosed, wherein a correction parameter is determined for a reagent signal, describing the amount of reagent to be introduced into the exhaust system and the correction parameter is determined by means of a comparison of a measure of the actual amount of the reagent in the exhaust system, which should be introduced based on a measure of a pre-determined set amount and the measure of the set amount. The above method permits a particularly exact maintenance of the amount of reagent introduced into the exhaust system in accordance with the pre-determined measure for the set amount.