I'm tryna see something. When I brake, when I slow down to a certain speed it would go down to like 800 rpms like normal but before going to the proper idle speed the rpms jump to like 1200. Mostly it does it twice. It even jerks when I shift in any gear. It idles high, like 1200 sometimes. When coasting, it doesn't slow down how it pose to, rather it may even slowly speed up. Is all of that may be a transmission problem or what? & im running a 1988 f150, 302 with AOD tranny

 

My 96 was doing something similar to what you're describing. It ended up being the throttle positioning sensor. Here's a link that should help troubleshoot it.

http://easyautodiagnostics.com/ford/...sensor-tests-1

 

Could also be sticky throttle linkage or IAC. The AOD has a TV cable, that may need adjustment.