Abstract: The invention relates to a method for operating a diesel engine in which an air ratio (?) of the fuel which is to be burnt and of the combustion air supplied is set by a control unit (14) according to predetermined values. When a value (15) which is predetermined as a switching criterion is recorded, the control unit (14) switches to a special operating mode for regeneration of a catalytic converter (22) and sets the fuel/air ratio according to predetermined values for this operating mode. To achieve more effective regeneration of the catalytic converter, according to the invention it is provided that at least one afterinjection, which is separated in time from a main injection, of fuel which is also to be burnt takes place in the special operating mode.

Abstract: The invention relates to a method for operating a diesel engine in which an air ratio (&lgr;) of the fuel which is to be burnt and of the combustion air supplied is set by a control unit (14) according to predetermined values. When a value (15) which is predetermined as a switching criterion is recorded, the control unit (14) switches to a special operating mode for regeneration of a catalytic converter (22) and sets the fuel/air ratio according to predetermined values for this operating mode.

Abstract: The invention relates to a method of operating a diesel engine having an engine controller which controls the operation of the diesel engine as a function of characteristic maps and permits rich/lean control of the diesel engine. The engine controller includes a computer which effects a changeover to rich or lean operation of the diesel engine as a function of predetermined changeover criteria, a sensor system which communicates with the computer and monitors parameters needed for changeover criteria, and a memory which communicates with the computer and in which the characteristic maps for operating the diesel engine are stored. The computer effects a changeover from lean to rich operation when all the changeover criteria in this respect are satisfied, and effects a change back from rich to lean operation when at least one of the changeover criteria in this respect is satisfied.

Abstract: A multi-cylinder air-compressing injection-type internal-combustion engine having a nitric oxide adsorber catalyst and an exhaust gas return device. In order to increase the hydrocarbon fraction in the exhaust gas in front of an exhaust gas aftertreatment device during a regeneration phase and to reduce the oxygen content, exhaust gas pipes of the cylinders are divided into at least two flows, which extend separately from one another at least along a distance. An increased hydrocarbon emission is generated exclusively in the cylinders of one of the flows at times. Another of the flows is connected by way of the exhaust gas return device with an air intake pipe of the internal-combustion engine.

Abstract: A system and a process for operating a diesel engine using an automatic engine control which, as a function of characteristic diagrams, automatically controls the operation of the diesel engine and permits an automatic rich/lean controlling of the diesel engine. The automatic engine control includes a computer which, as a function of predetermined change-over criteria, causes a change-over to the rich or the lean operation of the diesel engine. A sensor system communicates with the computer and monitors the parameters necessary for change-over criteria. A memory communicates with the computer, the memory storing separate characteristic diagrams for the operation of the diesel engine for the lean operation and for the rich operation.