Residual fuel amount-estimating system for fuel tank of internal combustion engine

摘要

A residual fuel amount-estimating system for a fuel tank of an internal combustion engine installed in a vehicle. A pressure sensor detects the pressure within the fuel tank. The interior of the fuel tank is negatively pressurized, and a rate of change in the pressure within the fuel tank during negative pressurization is detected. A residual fuel amount within the fuel tank is estimated, based on the detected rate of change in the pressure within the fuel tank.