Ford Repair: 1986 bronco-2 idle problems, ford bronco 2, coolant temp

Question
i have a 1986 ford bronco-2 with the 2.9 v-6, when i start it in the morning it with start fine then will rev-up a bit then idle down to far and die,it will do this until engine is warmed up.idle goes up and down even when warmed up. its had this problem for a couple of years now ,its just getting worse.Ive replaced the coolant temp sensor.the iac control valve,iat sensor,tp sensor,and still does the same thing ,i need help .please.i cant figure this one out.thx tulkster

Answer
Rick,

I would start by cleaning the throttle body and IAC really good. Next, check your ignition timing making sure the spout is unplugged while you set it. I believe the spec is 10 degrees BTDC. Now with everything hooked back up start the engine again and let it fully warm up and idle. Now unplug the IAC motor with it running. The engine should do a "rolling stop" where the idle drops so low that it finally stalls out.  If it doesn't stall you can re-adjust the throttle stop screw until the throttle plate closes enough to stall it out. Last disconnect the battery negative side for a few minutes and re-connect it. Start the engine and allow it to re learn the new idle settings. It may stall a few times at first, but that is normal.

Let me know if you have any more problems with it.