Abstract: A method detects a “misfire” condition in an internal-combustion engine including a control unit, a driving shaft and phonic wheel that is splined to the shaft and coupled to a sensor. The method comprises steps of: detecting intensity of a signal generated by passage of teeth of the wheel by the sensor, sampling the signal generated by the passage of the teeth, processing the sampled signal by applying a discrete Fourier transform, representing the sampled signal processed by a virtual phasor that represents in a vector form the signal that has been sampled and processed, determining a corresponding theoretical phasor for the virtual phasor that represents theoretical evolution of the signal that has been sampled and processed over time, comparing the theoretical phasor with the virtual phasor, and determining presence of a “misfire” condition by comparing the theoretical phasor with the virtual phasor that represents the signal that has been sampled and processed.

Abstract: A method detects a “misfire” condition in an internal-combustion engine including a driving shaft and phonic wheel that is splined to the shaft and coupled to a sensor. The method comprises steps of: detecting intensity of a signal generated by passage of teeth of the wheel by the sensor, sampling the signal generated by the passage of the teeth, processing the sampled signal by applying a discrete Fourier transform, representing the sampled signal processed by a virtual phasor that represents in a vector form the signal that has been sampled and processed, determining a corresponding theoretical phasor for the virtual phasor that represents theoretical evolution of the signal that has been sampled and processed over time, comparing the theoretical phasor with the virtual phasor, and determining presence of a “misfire” condition by comparing the theoretical phasor with the virtual phasor that represents the signal that has been sampled and processed.

Abstract: A fuel volatility recognition method during the post-cranking step of an internal combustion engine; the recognition method contemplates the steps of: starting the internal combustion engine; adjusting the enrichment of the mixture burnt in the cylinders of the internal combustion engine according to a previously determined historic fuel volatility value; detecting the time evolution of the angular speed of a crankshaft of the internal combustion engine during the post-cranking step; determining the noise contained in the angular speed of the crankshaft by filtering the angular speed itself by means of a high-pass filter; comparing the noise contained in the angular speed of the crankshaft against at least one predetermined threshold value; and recognizing the fuel volatility according to the result of the comparison between the noise contained in the angular speed of the crankshaft and the predetermined recognition threshold.