Abstract: A method for testing the function of a high-pressure pump having a plurality of pump elements, which each define a respective work chamber which is in communication, via a suction valve with a low-pressure region, from which fuel can be aspirated, and via a pressure valve with a high-pressure region which includes a central high-pressure fuel reservoir, serving to supply fuel to an internal combustion engine, into which high-pressure reservoir the high-pressure pump pumps the fuel aspirated from the low-pressure region, and the pressure of which is detected by a rail pressure sensor. The values detected by the rail pressure sensor are used in the built-in state of the high-pressure pump in operation of the engine for testing the function of the high-pressure pump.

Abstract: A method for testing the function of a high-pressure pump having a plurality of pump elements, which each define a respective work chamber which is in communication, via a suction valve with a low-pressure region, from which fuel can be aspirated, and via a pressure valve with a high-pressure region which includes a central high-pressure fuel reservoir, serving to supply fuel to an internal combustion engine, into which high-pressure reservoir the high-pressure pump pumps the fuel aspirated from the low-pressure region, and the pressure of which is detected by a rail pressure sensor. The values detected by the rail pressure sensor are used in the built-in state of the high-pressure pump in operation of the engine for testing the function of the high-pressure pump.

Abstract: A pressure-control valve for regulating the pressure in a fuel accumulator having a piston-shaped valve member guided axially displaceable in a bore and acts on a closing element which can be pressed against a valve seat. The valve member constitutes an armature of an electromagnet which can be supplied with electrical current. The valve is additionally equipped with a mechanical spring which presses the valve member in the direction toward the valve seat and whose initial spring tension is such that the spring pressure corresponds to the maximum desired pressure in the fuel accumulator. In this way a pressure is generated at the valve outlet and therefore an injection process is made possible, even in case of a failure of the electromagnetic regulation.