[Greg Reid]

The pulloff is adjusted and I believe it's correctly adjusted. There are no leaks in the diaphragm. The carb runs very, very well. No coughing, no flat spots, great idle. The ONLY issue I have is the one I've described. I'm pretty meticulous with that kind of stuff and even fabricated a reducer to go in the diaphragm line to adjust the pull-off dropout time. I set the gap in the choke valve using a drill bit...can't remember what the specs were now but it was set.
The engine starts cold with high idle just like I want it to, just drops out a little quick when the engine is cold and comes in a little quick when the engine is warm. This is really the essence of my issue.
I can look at all of those adjustments again as I think it was summer when I originally set it up. I remember leaning the choke spring just a tad when I first finished everything because I did not like the bit of black smoke when the choke was fully cold. Leaned it out just a bit and got rid of that but now the choke will lean out just a tad colder than I would prefer.
Maybe the cold weather requires me to take few minutes to check everything over again...?
Again, none of it is a major issue. I rarely drive it in cold weather but I did this past weekend. Otherwise, I may have never noticed it going back to hi idle after being shut down probably 3 minutes tops.
It's a 1974 carb by the way and also, just as a point of interest, I have rebuilt 4 of these carbs using Cliff's recipe and quite a few others before I knew to do anything other than disassemble, clean and reassemble so it's not like my very first rodeo on this.
I'll take a look at the chevelle site and see if there's anything there that opens my eyes to something I completely did not know about in that dept.