Method for detecting the start of combustion in cylinder of internal combustion engine

The procedure for determining the commencement of a combustion in the cylinder in internal combustion engine includes taking a series of measured values and storing them, and which describe a physical characteristic of the gas and fuel mixture in the cylinder. An average value is calculated from the last stored measured value and a predetermined number of measured values which directly precede the last stored measured value in the series. A difference is formed between the last calculated average value and last stored value and compared with a threshold value.