Patent ID: 6886543

Claim:
A fuel supply control system for an engine, comprising a composite control valve which is constructed by a valve housing, a negative pressure working chamber defined in the valve housing to communicate with a negative pressure generating section in the engine, a first control valve operable to be opened and closed with generation and extinction of a negative pressure in the negative pressure working chamber, and a second control valve operable to be opened and closed with the generation and extinction of the negative pressure in the negative pressure working chamber, the first control valve being incorporated into an air vent system which provides communication between an upper space in a fuel tank and the atmosphere, the second control valve being incorporated into a fuel passage system which provides communication between a portion of the fuel tank below a fuel oil surface and a fuel supply section in the engine, at least a portion of the air vent system being constituted by an inner air vent pipe disposed within the fuel tank, a gas-liquid separating means being provided in an opening of the inner air vent pipe into the upper space, the gas-liquid separating means being adapted to inhibit entrance of a fuel within the fuel tank into the inner air vent pipe and to permit the ventilation.