Research on Estimating Fuel Injection Time Using Crankshaft Rotational Changes for FI System of Small Motorcycle Single Cylinder Engine

In the fuel injection system, an intake pressure sensor is usually attached in the intake pipe to estimate the amount of intake air into the engine. The intake air flow rate is correlated with peak intake pressure (P_in) in the intake pipe measured by the intake pressure sensor. Authors experimentally analyzed the correlation between the intake air flow rate and the crankshaft rotational fluctuation. Moreover the feasibility to estimate fuel injection time duration from the crankshaft rotational fluctuation without the intake pressure sensor was studied.