A method is provided for determining an in-cylinder pressure curve representative of the evolution of the pressure within a cylinder of a multi-cylinder internal combustion engine. The method includes, but is not limited to setting a timeframe during the engine functioning, sampling pressure within at least two sensed cylinders of the engine, the samplings being performed during not contemporary sampling periods within the assumed timeframe, in order to acquire a partial in-cylinder pressure curve for each of the sensed cylinders, and using the partial in-cylinder pressure curves for reconstructing a whole in-cylinder pressure curve.