Internal combustion engine having exhaust emission control system

摘要

The characteristics of an exhaust emission control system can be varied by bleeding air into a vacuum conduit through which a vacuum is applied to a vacuum actuator in the exhaust emission control system. Means for bleeding air into the vacuum conduit includes at least one replaceable orifice. Another ambient air bleeding means comprises three plates which are joined face to face to one after another to form internal fluid connections between pressure and vacuum conduits through which intake passageway vacuum is applied to a vacuum actuator in an exhaust emission control system. One of the three plates is formed with a plurality of air bleed control orifices and can be easily replaced with another one.