I have an AFB 4055S on otherwise stock 300. Car idles properly at around 750rpm in gear and close that in gear with a/c on and idle solenoid engaged. Problem is that with a/c on at idle, engine will load up and eventually die. No a/c everything works fine. On the highway, with a/c on, seems fine until you step down on it, then it sputters and acts like it swallowed something eventually clearing up and running ok. I have tried carb cleaner injected down vents and with car running, no change. Carb was rebuilt three years ago. Car gets frequent use, rarely sitting up for longer than a month. All this only happens with a/c on. Time for a rebuild?? If so who is the guru on AFB's? Oh yea, running with a/c is mandatory here in Louisiana, unless you like sticking to the seats. Thanks for any help.