Electronic fuel control system is employed in automobiles to determine accurately and precisely the mass air flow rate into the engine. Electronic fuel control system also performs the task of regulation of fuel delivery with optimum precision. The fuel delivery regulation is in such a way that the ratio of the mass of air to the mass of fuel in each cylinder is as close as possible to stoichiometry. The main components of a electronic fuel control system are throttle position sensor, mass air flow sensor, ignition systems, fuel injectors, engine coolant sensor, engine position sensor and exhaust gas oxygen sensor. Fuel injectors regulate fuel delivery and ignition systems sets optimum ignition timing. Crankshaft angular speed is measured by engine position sensor. Output signal generated by exhaust gas oxygen sensor is dependent on the concentration of residual oxygen in the exhaust after combustion.