Automobile engine misfire detecting method
AssigneeHyundai Motor Company
InventorYoung-Kyo Chung
Life of this patent
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Abstract
An automobile engine misfire detecting method adapted to use a wide—range oxygen sensor mounted at a gas exhausting system wherein an abrupt man—made concentration change of oxygen is generated prior to entry of conventional misfire detection judging logic and response characteristic of wide—range oxygen sensor is measured therefrom, on which standard value of misfire detection judgment and standard phase angle range for distinguishing misfired cylinder are corrected to perform the misfire detection and misfired cylinder discrimination, thereby enabling to minimize the influence caused by aged wide—range oxygen sensor and characteristics of each sensor and to effect a more accurate detecting operation.
Claims5
An automobile engine misfire detecting method comprising the steps of:
- abruptly decreasing fuel injection under a predetermined engine operation condition by a predetermined amount to measure changes of signals from a wide—range oxygen sensor before and after the fuel injection decrease;
- correcting a standard value for judging misfire according to changes of signals from the wide—range oxygen sensor measured at the sensor characteristic measurement step;
- judging if a misfire has occurred by discriminating if a fluctuated incline curve of the signal from the wide—range oxygen sensor has surpassed the corrected standard value;
- calculating a phase difference between a standard pulse of a phase sensor and a second peak at the fluctuated incline curve of the signal from the wide—range oxygen sensor at a time of misfire occurrence;
- and
- judging which corrected standard phase angle range in which the calculated phase difference belongs to discriminate in which cylinder a misfire has occurred.
Dependencies are inferred from the claim text.