Apparatus for diagnosing abnormality in fuel injection system and fuel injection control system having the apparatus
February 27, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesDiagnostic system of an air-fuel ratio control device Internal combustion engine with device for warning of malfunction in an air-fuel ratio control system Method of detecting abnormality in fuel supply systems of internal combustion engines Fuel delivery control apparatus for engine operable on gasoline/alcohol fuel blend Vehicle engine fuel system diagnostics Learning-correcting method and apparatus and self-diagnosis method and apparatus in fuel supply control system of internal combustion engine Apparatus for controlling the respective cylinders in the fuel supply system of an internal combustion engine Patent #: 5131372 InventorAssigneeApplicationNo. 842425 filed on 02/27/1992US Classes:123/690With fail-safe, backup, or malfunction meansExaminersPrimary: Nelli, Raymond A.Attorney, Agent or FirmForeign Patent References
International ClassF02M 051/00Foreign Application Priority Data1991-03-08 JPAbstractIn an apparatus for diagnosing an abnormality in a fuel injection system in which an injection quantity is feedback-controlled by adjusting a first air-fuel ratio correction value so that an air-fuel ratio is equal to a target air-fuel ratio. The injection quantity is also adjusted by a second air-fuel ratio correction value. When the first air-fuel ratio correction value has reached a first upper limit value, the second air-fuel ratio correction value is set to a second upper limit value. When the first air-fuel ratio correction value has reached a second lower limit value, the second air-fuel ratio correction value is set to a second lower limit value. When the first air-fuel ratio correction value is outside of a predetermined range when a predetermined time has elapsed after the second air-fuel ratio correction value is set to either the second upper limit value or the second lower limit value, it is determined that a fault has occured in the fuel injection system. | |
