In the fuel characteristics decision device which decides the characteristics

摘要

PROBLEM TO BE SOLVED: To precisely judge fuel property even in an engine of D JETRO or α-N method equipped with no intake air quantity sensor in addition to an engine of L JETRO method equipped with an intake air quantity sensor.;SOLUTION: The engine speed integrated value ΣNe and the fuel injection quantity integrated value ΣTi are calculated for a prescribed time from the start of the engine, respectively (Steps 103 and 104). The integrated value ratio ΣNe/ΣTi is determined, and the fuel property by volatility is judged by the comparison of the integrated value ratio ΣNe/ΣTi with a predetermined judgment threshold FN (Steps 107-109).;COPYRIGHT: (C)2001,JPO