my truck recently started to idle low when cold. it runs and goes fine but unless its up to temp if i let out of the throttle (where it should idle at like 850) it drops to about 200-300. it also idles fine driving until i come to a stop and hold the brake then again it drops severly. i thought it might be the fuel filter so i changed it and it didnt help at all. anyone seen this before?
thanks

 

I seen this High Idle Systems for Dodge and Cummings Engines

 

have you put a fuel plate in you pickup if so they say each time you mess with the plate the rpm idiling will slightly decrease in my 1996 i recently put a # 0 fuel plate and it went from idiling from 900 to about 500 when cold and 800 when wormed up now. i got my info from ocha cummins