METHOD FOR DIAGNOSING THE CONDITION OF AN ENGINE FUEL SUPPLY SYSTEM

摘要

A method for diagnosing a condition of a system for supplying fuel to a fuel injected controlled-ignition internal combustion engine, of a type including an electric control device that makes use of an oxygen probe for closed-loop regulation of a value of an air/fuel ratio admitted to the combustion chambers of the engine, and according to which a signal delivered by the oxygen probe is analyzed, the method a) deducing from the signal a change in injection time correction factor ALPHACL_MEAN making it possible to regulate richness of exhaust gases leaving the engine; b) comparing ALPHACL_MEAN against predetermined minimum and maximum threshold values THRESHOLD_MIN and THRESHOLD_MAX; c) diagnosing a defective condition when ALPHACL_MEAN is outside of a window included between THRESHOLD_MIN and THRESHOLD_MAX.