Method of determining the composition of fuel in a flexible fueled vehicle without an O2 sensor

摘要

The present invention is directed towards a method of controlling combustion parameters of an internal combustion engine prior to oxygen sensor feedback availability for a flexible fueled vehicle. If the vehicle has previously been running on ethanol or has been using ethanol in the recent past, a first strategy is employed which basis engine fueling on the minimum of a theoretically appropriate fueling value and a theoretically calculated value. If the vehicle has not previously been running on ethanol or has not been using ethanol in the recent past, a second strategy is employed which basis engine fueling on the minimum of the theoretically appropriate fueling value, the theoretically calculated value and a roughness calculated value.