Method of determining a fuel tank vapor flow rate

摘要

A method is provided for accommodating the purge vapors from an evaporative emission control system of an automotive vehicle. The method includes a means of learning the flow rate of purge vapors from the fuel tank. The fuel tank model uses the output of a strategic adaption routine to learn the tank vapor flow rate. This flow rate is used to maintain fuel to air control under varying air flow and purge flow conditions especially under return-to-idle situations. As such, the fuel to air ratio at the injectors can be controlled under varying air flow and purge flow conditions to improve drivability and emissions.