Electronic devices in automotive area have been used on large scale and a control unit is mandatory for greater engine efficiency. By performing the spark advance and injection timing correctly in internalcombustion engines, an engine control unit improves drivability and helps to reduce fuel consumption. Before ECUs, air-fuel mixture, ignition timing, and idle speed were mechanically set and dynamically controlled by mechanical and pneumatic means. The fuel injection system has the major role to control the engine’s fuel supply. The application of soft computing technique for Electronic Fuel Injection improves the efficiency of the system. Our project is to develop a state flow based Electronic Fuel Injection system for a Single Cylinder Spark Ignition Engine. State Flow based model is designed and developed in MATLAB. To validate the simulation results, state flow is implemented in a Microcontroller. Further as the Electronic Control Unit is programmable, it could be used to enhance the performance of different Engines.