I replaced the thin vacuum line between the decel valve and the throttle housing and that seems to solve the issue. $3 at autozone is more than a golf tee though..,,,

On the 80-83 the decel valve sticks and leaks when it gets older. (the pancake) Also the rest of the system ages as well and the air bypass it creates causes issues. So a new pancake and a functioning CIS system will correct this.

Yea, it's more expensive than a golf tee I know. However when it's all working it's near nirvana for a CIS system.

911 SC idle problem
 

I would like to follow-up on my previous post for completeness:

I thought the new vacuum line fixed it, but the high idle with warm engine continued the next day (my previous post was premature exuberance).

I suffered with the issue for a few months and then finally got fed up. I pulled out the "pancake shaped part" on the oil filter side of my '83 engine. It's actually called the vacuum limiter (930-110-190-00); it took me a while to decipher the previous posts for the '83 engine configuration.

I pulled the limiter out and noticed some sludge in the nozzle that goes to the AAR. I cleaned out the sludge with some Break-Free and pipe cleaners/q-tips. I also applied the vice squeeze fix to make it more pancake-like. Either way, the problem is fixed. So far no issues after a week.

I expect that the sludge was clogging the pipe. I kind of think the vice-squeeze fix is a bit of voodoo, but something worked.

http://forums.pelicanparts.com/uploa...1366051516.jpg

My 77 does this. Nice 900rpm on start then once warm the idle is 2100.