Had some time yesterday,so I thought I would go looking for the idle speed adjustment screw at the carburetor(Quadrajet 4 barrel on stock 305).I found the adjustment screw,hiding under and behind this:

http://i174.photobucket.com/albums/w119/fleetline51/DSC00482.jpg

It appears to be some type of solenoid that regulates the throttle.I removed it to bench test it and it functions when voltage is applied.I cleaned it and replaced it without much further thought,but this morning it occurred to me that it has some type of dedicated function.

Could this be the cruise control throttle solenoid? No other voltage was present at the solenoid when I checked for current flow,but then again, the cruise control was not engaged at the time.

Thanks for your help!

Best Regards,

Tony :beer:

THese are used to speed the idle up slightly when the AC is on

yep

cruse is conected to the carb with a cable or vaccum actuator,,and mounted to the left inner fender,,iirc.:texas:

That's the "ANTI DIESEL SOLINOID".
With Ign. on, voltage is applied to it, plunger on it
pops out a bit and raises the idle speed to it's set
adjustment [ie ~ idle speed].
When you shut the engine off, it pops back in,
preventing engine run on, or dieseling, by droping
the idle lower than needed to run the engine.
But hey ~ What do I know?:dontknow:

Larry could also be correct. During the 80s with the leaner fuel mixtures and higher idle speeds the engines tended to diesel when the key was turned off, and the solinoid functioned as Larry described.

It will depend on what it's wired to.