I have a 98 dakota with a 3.9 in it, and i have been having problems with it idling. When the truck is completly cold it will start up and idle fine, however if you shut it off and try to start it back up while it is still warm it doesnt want to idle. If you pull the negative battery terminal off and reset the ecu, it will run fine for awhile then start doing the same thing. I cleaned the iac port on the throttle body and replace the iac valve (with a used one i had laying around) it ran fine for awhile then started doing the same thing. Anyone have any ideas what it could be? Should i try replacing the iac with a brand new one?