If your engine is all original, it is a little involved. If your engine is original, it has a computer that controls everything, including the idle speed using a DC motor. This system worked well when it was new, but now it's hard to diagnose and get parts for. I converted mine over to a regular carb and distributor, but some of the distributors are getting hard to find.
Mine would run good when I got it, but randomly I would also get the 2K rpm thing. I found out is was the computer advancing the timing for some reason. I am going to attach the factory idle setting procedure for your 2.8.
