1987 R10 5.0L

did you look and see if the throttle plates are stuck open some ? your Idle air controll might be stuck wide open ( they allow air to by pass throtttle plates at closed throttle and let ECM to adjust RMP , fast idle on start up...AC command ...stuff like that ..... also if air is sucking in from somewhere else ..call a vacume leak ..look for vacume hose off . if you got plyers , temporary pinch off hose to brake booster ..case brake booster screwed up ......also if you got cruise controll make sure its not hanging up , EGR could be stuck open but i doubt it , they usualy run like crap, dump black smoke out pipe , you can use water in a spray bottle with engine running , if RMP isn't 4000 and above .lol spray water around TBI gasket and Intake were it meet cylinder head , if RPM changes or engine stumble you may have found your prob.. .TBI on your year of truck were bad for sucking in the base plate gasket , Thats under the throttle body unit ...easy fix replace gasket ... if you got a can of air intake cleaner ( similar to carb cleaner ) spray around tbi gasket , or like i said up top water will work but dont spray into throttle body , and goes easy around base plate ...hope

hope this helps some

- "TM" wrote in message news:e5zwg.40116$ snipped-for-privacy@tornado.ohiordc.rr.com...

Tried most of these, but I'll go over the list again.

Thanks for the info, and I'll post what I find.

Rigid vaccuum line to the brake booster had rusted thru....Swapped it out and all is good now...

thanks for the help.