Internal combustion engine, method for auto-ignition operation and computer readable storage device

The invention relates to an internal combustion engine comprising a fuel injector (2) for each cylinder; a fuel injection control unit (4) for controlling fuel injection quantity and a piston (5) in each cylinder whose compression action causes a mixture of air and fuel to be ignited. The engine is further provided with inlet and outlet valves (6, 7) and various sensors (12-16) for measuring various engine operating parameters. During compression ignition mode, the control unit (4) is arranged to select a lambda -value from a map stored in the control unit, which value is a function of engine load and engine speed, and to compare the actual lambda -value with the selected lambda -value; whereby the control unit is arranged to adjust the intake manifold pressure as a function of the difference between the said lambda -values in order to obtain the selected lambda -value. The invention further relates to a method for operating the engine and a computer readable storage device (4).