Abstract: An air fuel ratio control for an I.C. engine fuel supply system is disclosed including a diaphragm operator for a fuel flow modulating valve responsive to engine intake manifold pressure as sensed through an air line connecting the diaphragm operator with the intake manifold and a drain line for returning to the engine fuel tank all fuel which may leak into the diaphragm operator due to seal rupture. The disclosed system further including a specially designed flow restrictor in the air line to prevent engine fuel tank pressurization and reverse fuel flow into the engine's intake manifold should the diaphragm operator rupture. The flow restrictor includes a control orifice which is sufficiently large to allow proper control by the diaphragm operator but yet not so large as to allow fuel tank pressurization should the diaphram rupture. In one embodiment the flow restrictor includes a check valve designed to close only upon improper fuel flow from the air fuel control to the intake manifold.

Abstract: This disclosure deals with a fuel injector for an internal combustion engine. The injector includes an injector body having a fuel metering chamber formed therein which receives fuel from a fuel supply. A plunger is movable into the chamber in an injection stroke to force fuel from the chamber and out of the injector through spray holes. A valve member is mounted in the path of fuel flow from the chamber to the spray holes, the valve member being movable between first and second positions. In the first position, the valve member seals the path and prevents air in the combustion chamber from mixing with the fuel being metered into the metering chamber, and in the second position the valve member closes the spray holes to terminate injection. During an injection stroke, the plunger moves the valve member from the first position toward the second position, and fuel injection takes place while the valve member is intermediate the first and second positions.