[Dave63]

As part of regular service, there's a pintle valve, just inside the throttle body, at 12-o"clock. Its for the idle air contril (IAC) valve. Spray it with carb cleaner, with the tiny hose that comes with the can, and make sure you get up and unto that passage. You likely have carbon/dirt build-up in there.

#1- IAC motor

#2 - IAC pintle/port

 

[Dave63]

I believe, based on the rubber vent caps, Screamin Eagle.