Method and system for controlling the combustion of an internal combustion engine

A method for controlling combustion in an internal combustion engine having a single cylinder or a butterfly throttle valve for each of a plurality of cylinders, said internal combustion engine including an air inlet pipe provided with a regulator configured to regulate the flow of air in said air inlet pipe, the single cylinder or the plurality of cylinders being associated with said regulator, said internal combustion engine operating based on a four-stroke engine cycle, the method comprising:

• determining one or more of an engine speed and an engine load;
• and
• operating the regulator to temporarily reduce an air flow during one of the four-stroke engine cycles compared with a position that said throttle valve occupies during other strokes of the respective four-stroke engine cycle, while an intake valve that lets air from said inlet pipe into the corresponding cylinder is open or at least for part of the time that the intake valve is open, when one or more of:
• (i) the determined engine speed is below a predetermined engine speed value, and (ii) the determined engine load is below a predetermined engine load value.