Fuel Delivery Control

The ECM controls fuel by receiving input signals from various sensors. It then takes this information and calculates the amount of fuel required to achieve a specific air/fuel ratio. The ECM controls the fuel flow into the engine by controlling each injector individually. This system is called Sequential Fuel Injection (SFI). The injection are pulse width modulated based primarily on ECT, rpm, and MAF inputs to the ECM. Other secondary contributes are also evaluated by the ECM in determining injector on time. Once the engine temperature is sufficient for closed loop operation, the ECM considers oxygen content of the exhaust stream. Based on this input, the ECM may increase or decrease injector on-time to regulate the oxygen content of the exhaust stream.