ok so I have a fully rebuilt 89 mustang 5.0 in my 86 ranger. the engine is pretty much stock besides it has the E-303 cam. It starts and runs fine when cold and even when its warm but just somtimes if I let it idle for a while like in a drive thu it idles like this (posted link to video) i pulled codes and the only ones i got were KOEO 95-67-84 memory were 29-33-95
http://s544.beta.photobucket.com/user/motocross401/media/Picture019_zps20ca06c0.mp4.html
http://s544.beta.photobucket.com/user/motocross401/media/Picture019_zps20ca06c0.mp4.html