Abstract: A fuel sensor (20) includes a single capacitor (22) that operates in two different modes to obtain capacitance and conductance information when a fuel mixture flows between the electrodes (24, 26) of the capacitor. Two different oscillators (180, 182) are selectively used to obtain the conductance and capacitance information. In a disclosed embodiment, a capacitor includes an outer electrode (24) that is received around an inner electrode (26) such that there is a spacing between the electrodes through which the fuel flows. The fuel acts as a dielectric of the capacitor allowing the conductance and capacitance measurements to be made. The inventive fuel sensor can be readily incorporated into a variety of locations within a vehicle fuel supply system depending on the needs of a particular situation. In one example, a portion of the fuel rail (132) is used as one of the electrodes of the capacitor.

Abstract: A portable fuel analyzer includes a sensor, a processor and a display. The portable analyzer receives a fuel sample and the display identifies whether the vehicle fuel is tainted. The portable fuel analyzer is linked to an evaluation unit to determine a frequency measurement based upon signals from the sensor in the portable fuel analyzer. The evaluation unit provides a method of comparing the frequency from the vehicle fuel sensor with the frequency from the portable fuel analyzer. If the green LED is illuminated and the portable fuel analyzer indicates a different frequency than the vehicle fuel sensor, the vehicle fuel sensor is defective and should be replaced; If the green LED is illuminated and the portable fuel analyzer indicates the same frequency as the vehicle fuel sensor, a vehicle component other than the vehicle sensor is faulty; and, if the red LED is illuminated, the mixed fuel sample is tainted and a determination about the vehicle fuel sensor cannot be determined.

Abstract: A fuel sensor (20) includes a single capacitor (22) that operates in two different modes to obtain capacitance and conductance information when a fuel mixture flows between the electrodes (24, 26) of the capacitor. Two different oscillators (180, 182) are selectively used to obtain the conductance and capacitance information. In a disclosed embodiment, a capacitor includes an outer electrode (24) that is received around an inner electrode (26) such that there is a spacing between the electrodes through which the fuel flows. The fuel acts as a dielectric of the capacitor allowing the conductance and capacitance measurements to be made. The inventive fuel sensor can be readily incorporated into a variety of locations within a vehicle fuel supply system depending on the needs of a particular situation. In one example, a portion of the fuel rail (132) is used as one of the electrodes of the capacitor.

Abstract: A portable fuel analyzer includes a sensor, a processor and a display. The portable analyzer receives a fuel sample and the display identifies whether the vehicle fuel is tainted. The portable fuel analyzer is linked to an evaluation unit to determine a frequency measurement based upon signals from the sensor in the portable fuel analyzer. The evaluation unit compares the frequency from the vehicle fuel sensor with the frequency from the portable fuel analyzer. If the green LED is illuminated and the portable fuel analyzer indicates a different frequency than the vehicle fuel sensor, the vehicle fuel sensor is defective and should be replaced; If the green LED is illuminated and the portable fuel analyzer indicates the same frequency as the vehicle fuel sensor, a vehicle component other than the vehicle sensor is faulty; and, if the red LED is illuminated, the mixed fuel sample is tainted and a determination about the vehicle fuel sensor cannot be determined.