Okay, I don't know why my post got cut off like that. TLDR, my issue is an off idle stumble that appears when the car's warmed up and when the ambient temperatures are above 70-75*. On really hot days, it'll surge a little as you advance the throttle, but once you get good and going, it's fine. Cruises great, accelerates great (generally), but I'd like to cure this warm weather issue I'm having. Fuel filter has 27,000 miles on it, and I plan to change at the next opportunity. Curb idle mixture is appx. 3.5 turns out from lean, and the idle screw is almost all the way out. I haven't tried to get too liberal with the curb idle mixture, and I've heard that newer Q-Jets like more than pre-'73 units. It seems like a heat soak issue, but I'm confused as to why it's happening. The engine's running at normal temp, and while I have a nonthermal fan clutch, it's never given me any overheating issues. Car's a 1986 Chevy Caprice, 305 (E4ME). It will do the stumble in park, as I've tried to see if maybe it was the torque converter. It doesn't rule out a worn distributor issue, but it only does it at this very specific time and not all the time. @Cliff Ruggles
