I have an 84 TA with a 305 HO. When I first start it the engine races pretty bad at around 2000 RPM while it is idling. This is even on a warm sunny day. Then I'll drive it for a while and it will kick down and idle very rough at about 500 RPM which feels to low. Sometimes at this point if I try to accelerate it will stumble and almost die out. Then if I drive a little more the problems go away and it idles fine at around 800-900 RPM. Any thoughts?

Thanks

 

You may have the wrong choke coil on there. It sounds like the opening rate is too quick. Or, you are running lean and the car needs the choke to stay running until it is completely up to operating temp.