To cope up the burning problem of high priced and vanishing fossil fuels; with research in renewable energies, we should think for utilization of present amount of fuels in most efficient way. This need gives rise to advancement in design, construction and control of automotive engines. This has given rise to new generation of more developed, light, fuel efficient “High Tech” vehicles. Recent innovations in engine design and control have been adopted very widely and rapidly.

In this paper, we are concentrating on Control Systems in automobiles as these have direct contribution in fuel economy. For the engine to run, it must have good compression ratio, properly timed spark ignition, proportionate air-fuel mixture and enough hot sparks to ignite the mixture. If any of these conditions is missing, the engine won’t start or run properly and finally it affects fuel economy. Air-fuel Injection, Ignition, Exhaust Systems are the main components of control system.

The principle of Electronic Fuel Injection System is, the different sensors like TPS, CPS senses the changes in engine assembly and send electric signal to Electronic Control Module (ECM) which continuously calculates how much fuel is to be injected to achieve stoichiometric combustion. In the Ignition System, Knock, Throttle Position Sensors feed corresponding information to computer which decides correct timing of spark. This system of spark ignition can develop 47,000 V or more and produces longer and correct timed spark which ignites leaner air fuel ratios for better fuel economy and reduces exhaust emission.

In this paper, we are concentrating on Fuel Control Systems in automobiles as they have direct contribution in fuel economy and environmental safety. Fuel Injection, Ignition, Exhaust Systems are the main components of control system. All three systems are interrelated with each other and controlled by preplanned computer installed above the glove box within the passenger compartment called as ECM (Electronic Control Module).