Abstract: In a method and a device for the diagnosis of the effectiveness of a catalytic converter in the exhaust gas line when using a very late afterinjection or secondary injection, in order to provide a sensitive and yet robust diagnostic method while saving costs for additional exhaust gas temperature sensors and with fuel consumption increased only to a minimum extent, the diagnostic method delivering reliable results with only little delay, and a corresponding device which can also easily be used in various concepts for internal combustion engines, an increased compressor output, caused in the course of the test injection, of an exhaust gas turbocharger used downstream of the catalytic converter produce a higher charge pressure or a marked increase in the air mass flow (mL) such that the effectiveness of the catalytic converter is determined from a change in the intake air quantity of the internal combustion engine.

Abstract: In a method for determining an uncontrolled acceleration of an internal combustion engine, a valve opening cross section is allocated to each load state of the internal combustion engine. In the event that a controller value is outside a limit range, an uncontrolled acceleration of the internal combustion engine is thereby detected.

Abstract: In a method and a device for determining an operating characteristic of an injection system, to determine an operating characteristic (30) of an internal combustion engine (1) that is charged by a turbocharger (4), the method has the following steps: A) carrying out a pilot injection of fuel into a cylinder (51, 52, 53, 54) of the internal combustion engine using the injection system (30); B) determining an operating parameter of the turbocharger (40); C) determining an operating characteristic of the injection system (30) using the operating parameter of the turbocharger (40) previously determined.

Abstract: In a method of operating an internal combustion engine having at least two combustion chambers, each combustion chamber contributes torque to the total torque of the internal combustion engine, and the internal combustion engine is designed in such a way that a quantity of exhaust gas can be recycled into combustion chambers. The method has the steps: (a) detecting the torque contributions of at least two combustion chambers, then (b) changing the quantity of exhaust gas recycled into the combustion chambers, the torque contribution of which has been detected in step (a), then (c) detecting the torque contributions of at least two combustion chambers, the torque contribution of which has been detected in step (a), then (d) determining the change in the torque contributions as a result of the change in the quantity of recycled exhaust gas, and then (e) outputting a signal as a function of the change in the torque contributions.

Abstract: In a method and a device for controlling the fuel pressure in the pressure accumulator of a common-rail injection system, the difference between the actual engine speed and a target engine speed is established, and an injection time is determined based on the determined difference. The fuel pressure is controlled according to the determined injection time.

Abstract: In a method for adapting the performance of a fuel prefeed pump of a motor vehicle which has a common rail injection system and an internal combustion engine, after the ignition is switched on and before the internal combustion engine is started, adaptation values are determined and stored which are assigned to the fuel prefeed pump and describe its individual performance. After the internal combustion engine is started, the stored adaptation values are taken into consideration during the determining of an actuating signal for the prefeed pump.

Abstract: In a method for controlling a high-pressure fuel pump, which comprises an electrically controllable electromechanical inlet valve (2a) which is closed in the currentless state and is held in the closed state by the force of a spring (2b), an outlet valve (5a), and a displacement element (6), the inlet valve is operated in a self-controlling operating mode after a start command is present. In the self-controlling operating mode, the rail pressure is built without knowledge of the phase position of the displacement element. During the self-controlling operating mode, the phase position of the displacement element is determined. After the phase position of the piston or displacement element is determined, the inlet valve is switched over to a non-self-controlling operating mode.

Abstract: A method provides for detecting deviations of injection quantities for injections into internal combustion engines, as carried out for example by common-rail systems. At least one deviation of at least one injection quantity is detected by determining at least one deviation, from a predefined value in each case, of at least one value of at least one variable controlling an actuator of the injector and/or indicating at least one state of the actuator.

Abstract: In a method for determining the rail pressure in a common rail system of an internal combustion engine, at least one measurement variable is determined which is a measure for the angular velocity of a crankshaft movement of the internal combustion engine, and the rail pressure is determined from said measurement variable or from a variable derived from the measurement variable. Furthermore disclosed are methods that are based thereon for controlling an injection quantity and for controlling a rail pressure, and a corresponding common rail injection system.

Abstract: When the internal combustion engine is in an injection-free operating mode, a selected injector is open for injecting a small fuel amount, whereby at least one working cycle with injector control follows or precedes one cycle without control, a differential of two subsequent segment times of the cylinder associated with the selected injector or another variable, that reproduces a temporal crankshaft angle speed modification, is determined as a measurement value respectively for the cycle with and without control, and a relation is formed between the values of the cycles with or without control and used to correct the injection characteristic curve. The engine operates with active ignition and the value for the cycle with control is tested by taking into account ignition faults and the relation is only used to correct the curve if the value in the cycle with control significantly deviates from the one without control.

Abstract: A method for operating an internal combustion engine has the steps: (a) during an overrun phase of the internal combustion engine, activating an injector of a first combustion chamber for a predetermined activation time ?inj with a predetermined activation voltage Ui=1, (b) measuring a torque variation, (c) determining, from the torque variation, a fuel quantity mi=1 of the fuel injected by the injector during the activation time ?inj, (d) varying the activation voltage to a value Ui+1 which differs from Ui, (e) repeating steps (a) to (d) with further incrementation of i until i has reached a preset value N or the internal combustion engine is no longer in the overrun phase, and (f) determining an injector characteristic value of the injector of the first combustion chamber from the fuel quantities m1, m2, . . . , mN and the activation voltages U1, U2, . . . , UN.

Abstract: In a method and a device for determining an operating characteristic of an injection system, to determine an operating characteristic (30) of an internal combustion engine (1) that is charged by a turbocharger (4), the method has the following steps: A) carrying out a pilot injection of fuel into a cylinder (51, 52, 53, 54) of the internal combustion engine using the injection system (30); B) determining an operating parameter of the turbocharger (40); C) determining an operating characteristic of the injection system (30) using the operating parameter of the turbocharger (40) previously determined.

Abstract: In a method for determining an uncontrolled acceleration of an internal combustion engine, a valve opening cross section is allocated to each load state of the internal combustion engine. In the event that a controller value is outside a limit range, an uncontrolled acceleration of the internal combustion engine is thereby detected.

Abstract: In a method of operating an internal combustion engine having at least two combustion chambers, each combustion chamber contributes torque to the total torque of the internal combustion engine, and the internal combustion engine is designed in such a way that a quantity of exhaust gas can be recycled into combustion chambers. The method has the steps: (a) detecting the torque contributions of at least two combustion chambers, then (b) changing the quantity of exhaust gas recycled into the combustion chambers, the torque contribution of which has been detected in step (a), then (c) detecting the torque contributions of at least two combustion chambers, the torque contribution of which has been detected in step (a), then (d) determining the change in the torque contributions as a result of the change in the quantity of recycled exhaust gas, and then (e) outputting a signal as a function of the change in the torque contributions.

Abstract: In a method and a device for the diagnosis of the effectiveness of a catalytic converter in the exhaust gas line when using a very late afterinjection or secondary injection, in order to provide a sensitive and yet robust diagnostic method while saving costs for additional exhaust gas temperature sensors and with fuel consumption increased only to a minimum extent, the diagnostic method delivering reliable results with only little delay, and a corresponding device which can also easily be used in various concepts for internal combustion engines, an increased compressor output, caused in the course of the test injection, of an exhaust gas turbocharger used downstream of the catalytic converter produce a higher charge pressure or a marked increase in the air mass flow (mL) such that the effectiveness of the catalytic converter is determined from a change in the intake air quantity of the internal combustion engine.

Abstract: A common rail injection system for an internal combustion engine has at least one combustion chamber, a high pressure fuel pump for supplying fuel, a high pressure fuel accumulator connected to the high pressure fuel pump for storing fuel pinj at injection pressure in relation to the environment of the common rail injection system, an injector connected to the high pressure fuel accumulator for delivering fuel into the at least one combustion chamber, and a return line for returning fuel from the injector to the high pressure fuel pump. The fuel is pressurized by a return line pressure pdrain in relation to the environment of the common rail injection system. It is proposed that the common rail injection system has an adjusting means for adjusting the return line pressure pdrain. It is additionally proposed to use a pressure control means in the fuel leakage flow feedback system of an internal combustion engine.

Abstract: A method for operating an internal combustion engine has the steps: (a) during an overrun phase of the internal combustion engine, activating an injector of a first combustion chamber for a predetermined activation time ?inj with a predetermined activation voltage Ui±1, (b) measuring a torque variation, (c) determining, from the torque variation, a fuel quantity mi=1 of the fuel injected by the injector during the activation time ?inj, (d) varying the activation voltage to a value Ui+1 which differs from Ui, (e) repeating steps (a) to (d) with further incrementation of i until i has reached a preset value N or the internal combustion engine is no longer in the overrun phase, and (f) determining an injector characteristic value of the injector of the first combustion chamber from the fuel quantities m1, m2, . . . , mN and the activation voltages U1, U2, . . . , UN.

Abstract: In a method and device for characterising the return stroke of injectors, in particular piezo-injectors of an internal combustion engine provided with a common rail system, when the internal combustion engine is switched off, a constant pressure is dropped in the rail, thereby making it possible to measure the rail pressure and to adjust the injectors by corresponding power. The actuating power is increased until a discontinuity in a temporal progression of rail pressure occurs. The actuating energy applied for the state and a pressure available in the make it possible to measure the return stroke of corresponding injector.

Abstract: In an adaptation (4, 5, 6, 7) of differences in injected quantities within high operating ranges, the differences are based on an injection parameter and are determined by regulating an irregular operation in an operating point within the lower operating ranges. The injection parameter which determines the differences in injected quantities in the lower operating point is set on a value different from the normal operating value in this point. The dynamics of the operating point varying with the corresponding parametric value of injection is limited during adaptation (4, 5, 6, 7).

Abstract: A common rail injection system for an internal combustion engine has at least one combustion chamber, a high pressure fuel pump for supplying fuel, a high pressure fuel accumulator connected to the high pressure fuel pump for storing fuel pinj at injection pressure in relation to the environment of the common rail injection system, an injector connected to the high pressure fuel accumulator for delivering fuel into the at least one combustion chamber, and a return line for returning fuel from the injector to the high pressure fuel pump. The fuel is pressurized by a return line pressure pdrain in relation to the environment of the common rail injection system. It is proposed that the common rail injection system has an adjusting means for adjusting the return line pressure pdrain. It is additionally proposed to use a pressure control means in the fuel leakage flow feedback system of an internal combustion engine.