A self-igniting internal combustion engine includes at least one cylinder and a piston, which can be moved back and forth in the cylinder and which bounds a combustion chamber together with the cylinder and which has a piston recess facing the combustion chamber, said piston recess having flow cross-sections that vary in a circumferential direction of the cylinder and of the piston, and comprising an injector arranged centrally above the piston recess for injecting fuel into the piston recess, wherein the injector has a plurality of injection openings. In order to reduce the emissions and in particular the soot emissions of the internal combustion engine, at least some of the injection openings have different opening cross-sections, wherein the injection openings having the different opening cross-sections are directed at areas of the combustion chamber recess having different flow cross-sections.

An internal combustion engine has a fuel system that has a fuel valve with a housing, wherein in the housing a fuel chamber is formed. A fuel pump pumps fuel from a fuel tank into the fuel chamber. A conveying pump provides forced conveyance of fuel into the fuel system. A feed line is connected to the fuel chamber of the fuel valve. The conveying pump is arranged in the feed line and supplies fuel to the fuel chamber. A relief line is connected to the fuel chamber of the fuel valve and a first valve is arranged in the relief line.

An internal combustion engine has a fuel system that has a fuel valve with a housing, wherein in the housing a fuel chamber is formed. A fuel pump pumps fuel from a fuel tank into the fuel chamber. A conveying pump provides forced conveyance of fuel into the fuel system. A feed line is connected to the fuel chamber of the fuel valve. The conveying pump is arranged in the feed line and supplies fuel to the fuel chamber. A relief line is connected to the fuel chamber of the fuel valve and a first valve is arranged in the relief line.