Fuel delivery system for an internal combustion engine

摘要

A fuel delivery system for an internal combustion engine of the type having an intake manifold selectively fluidly connected to a combustion chamber and a bypass gas flow passageway having an inlet open to the intake manifold and an outlet open to the intake manifold downstream for the inlet is disclosed. The system includes an electronically controlled throttle valve operatively disposed in the intake manifold and movable between an open and a closed position to control air flow through the intake manifold. An idle speed control valve is operatively disposed within the bypass gas flow passageway, and the idle speed control valve is also movable between an open and a closed position to control air flow through the bypass gas flow passageway. A control system controls the actuation of both the throttle valve and idle speed control valve to control the delivery of a combustible charge to the internal combustion engine to maximize engine efficiency and minimize noxious emissions. Optionally, a cold start fuel injector is disposed within the bypass gas flow passageway to provide the fuel charge to the engine during a cold start condition. In an alternate form of the invention, two electronically controlled throttle valves are disposed within the intake manifold to control both the air flow through the intake manifold as well as the air flow through the bypass gas flow passageway.