Operating method of electric fuel pump in low pressure fuel system of internal combustion engine, involves changing opening timing of pressure limiting valve such that the actual performance reproaching value of fuel system is obtained

摘要

An operating variable of engine demand characteristic field is pre-controlled, and feed-forward control for providing tolerance compensation value is performed, based on the output of electric fuel pump (3). The selected operating state of fuel system is monitored for a certain period of time, to increase the delivery rate of pump, by the time of opening of a pressure limiting valve (12). The opening timing of the valve is changed, such that the actual performance reproaching value of the low-pressure fuel system is obtained.