LEAK DETECTION METHOD IN FUEL SUPPLY SYSTEM, AND LEAK DIAGNOSIS DEVICE IN THE FUEL SUPPLY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a leak detection method for a fuel supply system that detects a leak state in a fuel supply system of an internal combustion engine with high accuracy without depending on a pressure sensor and can perform an accurate diagnose, and to provide a leak detection method in a fuel supply system.;SOLUTION: The leak detection method seals a fuel tank to be an airtight state by a seal valve (S108). The leak detection method detects a deformation quantity in a profile of the fuel tanks as a deformation quantity ΔSGL between an initial fuel liquid level SGLini and a fuel liquid surface level SGLa after a predetermined time DTa passes by using a fuel sender gauge (S106, S110-S114). The leak detection method performs the leak determination (S116-S120) by the liquid surface change quantity ΔSGL. Since the leak determination is based on differences in the inside and outside of the profile, a pressure relationship between the inside and the outside is properly reflected, and an accurate leak diagnosis can be performed without using the pressure sensor.;COPYRIGHT: (C)2012,JPO&INPIT