Method of detecting abnormality in fuel supply systems of internal combustion engines
US5070847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1991 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Feb 1, 2011 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/2483
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method of detecting abnormality in a fuel supply system of an internal combustion engine. An amount of fuel supplied to the engine is controlled in a feedback manner based on an air-fuel ratio correction coefficient set in response to an output signal from at least one exhaust gas component concentration sensor. The method comprises the steps of (1) calculating an abnormality determination value based on the air-fuel ratio correction coefficient, (2) calculating a learned average value of the air-fuel ratio correction coefficient, (3) renewing the abnormality determination value when the calculated learned average value of the air-fuel ratio correction coefficient falls outside a first predetermined range defined based upon the abnormality determination coefficient, and (4) determining that the fuel supply system is abnormal when the renewed value of the abnormality determination value falls outside a second predetermined range defined by predetermined upper and lower limit values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.