Can anyone please tell me if the external idle vent on a Qjet 4 barrel is really needed? If the vent stays closed does it affect idle???
I've run my car with and without the vent operating and never noticed any difference. Some say its a good idea to deactivate it since dust and dirt can get in it, but its your call.
It Actually Prevents A Rich Idle Condition If The Carb Is Hot, They Eliminated It In Favor Of The Bi-metalic Compensator Spring You See On The Back Of Some Q-jets, They Later Vented The Fumes To The Black Canister You See On A Lot Of Cars. Hope This Helps
