i used the search, but did not find my symptoms.
what happens is. truck starts fine, runs great. driving along in city traffic (stop and go). engine starts to stumble at idle. i rev the thottle to keep it running. engine will rev up to 2000-2500 rpm. revolutions decrease, kind of a dropping surge. truck will move, but under full throttle, or light feathering of throttle, it will only go up to 2200-2500 rpm, dropping down to 1000-1500 rpm. that goes on for maybe 4-5minutes, then truck resumes normal operation. no problems, running great. help!

 

really, 114 views, and nobody has come across this before? somebody throw me a bone

 

did u change anything before this occurance?

 

Since it sounds like it only happens during warm-up, I would suspect the AAV/IACV/Air Valve whatever you want to call it, as I think it's the only thing that affects idle at warm-up. You can put a piece of duct or electrical tape over where the hose connects to the throttle body and see if that makes a difference. You won't have the idle up during warm-up, but if it still has the hesitation it's something else. Maybe replace the O2 sensor and test the TPS and AFM.

 

Also check vacuum lines, and make sure your getting fuel.

 

thanks!!! the only things i have worked on are frontend parts, balljoints, tie-rods, and rebuilt transmission/new clutch.
i appreciate the comments, will post up results.
hesitation, much better descriptive term.