Abstract: A method of calibrating the injectors of an injection system for an internal combustion engine which can compensate for the different flow rates of the injectors fitted in the engine, which are due to the production tolerances of the injectors, in order to re-match the injectors with consequent balancing of the combustion and overall improvement in the performance of the engine. The method is based on the determination of the flow rates of the injectors both with low admissions (idling) and with high admissions (acceleration) by measurement of the torque pulses supplied by each cylinder of the engine with the use of a dynamic torque measurement method.

Abstract: Starting from a sequence of values of indicated torque detected for each expected combustion in the engine a cycle signal is generated as a combination of at least two successive values of the said sequence. The peak value of the said cycle signal is then compared with a comparison threshold chosen preferably in proportion of the fuel injection duration into the cylinders. Misfires are identified preferably from the result of a comparison between the said peak value and the said comparison threshold which differs from the result of comparison in the presence of regular operation of the engine.