the invention relates to a diesel engine comprising a device for controlling the flow of injected fuel with at least one fuel injector supplying a combustion chamber , controlled by a processor provided with means for controlling a series of operations of the injector of differing durations , means for measuring a minimal activation time between the issuing of a command and the beginning of an injection and means for subsequently controlling the injector as a function of the measured minimal activation time . according to the invention , the engine is characterized in comprising means for determining the heat output brought about by the mixture of air and fuel injected into the chamber and to measure the minimum activation time using said determinations .