Fuel Control: Notes

The purpose of the fuel control system is to deliver the correct amount of fuel to the engine under all operating conditions. Fuel is delivered by the fuel injectors which are controlled by the ECM. The main control sensor is the oxygen sensor (O2S) located in the exhaust manifold. Sensor tells the ECM the amount of oxygen in the exhaust gases and the ECM changes the air/fuel ratio to the engine by modifying fuel injector pulse width. Fuel system operates in one of 2 modes: open loop or closed loop.