Abstract: A method and apparatus for operating an air-compressing, self-igniting combustion machine or engine, for liquid fuels, which has a combustion chamber depression, in the piston, into which fuel is sprayed or injected essentially centrally, preferably in a direction toward the depression wall, and in which the combustion air rotates at the time of injection. Oxygen-containing fuel that is reluctant to ignite is injected through an injection device into the combustion chamber depression, and an ignitible fuel is sprayed or injected through a second injection device, with an overlap in the injection times of the ignitible fuel and the oxygen-containing fuel that is reluctant to ignite. Ignition of the oil fuel, gas oil or Diesel fuel starts before injection of the oxygen-containing fuel that is reluctant to ignite. After approximately 2/3 of the injection time of the Diesel fuel, there begins the injection of the oxygen-containing fuel which is reluctant to ignite.