Fuel injection device for a spark ignition-type internal-combustion engine

摘要

The device meters fuel in a predetermined quantity ratio to the fresh air drawn in by the engine through the intake pipe (1) and controlled by a throttle valve (7). The fuel injection device contains an enrichment device (46) which increases the quantity of fuel added to the fresh air while the engine has not yet warmed up. A pressure sensor (85) for measuring the pressure prevailing in the intake pipe is additionally provided. According to the invention, this pressure sensor (85) deactivates the enrichment device (46) as soon as a certain vacuum, corresponding to the normal idling of the engine, is achieved in the intake pipe. This ensures that, when idling, the engine is always operated with a lean mixture when this can be tolerated, thus reducing consumption and improving the quality of the exhaust. As soon as acceleration occurs, the vacuum partially collapses and the enrichment device begins to function insofar as the engine has not yet warmed up. IMAGE