My buddy has a Vintage air in his ‘67 Belvedere. There’s a solenoid that’s wired to the compressor clutch that pops out to bump up the idle engine idle speed while in gear at a stop sign. He needs a few more RPM than what is set. We cured the problem with 4 layers of duct tape on top of the plunger.

The question for you guys is, will this plunger turn in or out to adjust the idle speed? I didn’t want to start trying to turn it until I got some more information. It appears to have a 1/2” or 9/16” size head on it.

Thx