Spark ignition internal-combustion engine operating method, involves dividing total amount of fuel supplied between injection units in catalyst-heating mode, where injection over one of injection units takes place during compression cycle

摘要

The method involves supplying fuel over a set of injection units (7, 8) in an operating region during an operating cycle. An internal-combustion engine (1) is operated in the operating region in a catalyst-heating mode. Total amount of fuel supplied between the injection units is divided in the catalyst-heating mode, where the fuel injection over one of the injection units (7) takes place before or during a suction cycle and the fuel injection over the other injection unit (8) takes place during a compression cycle.