i have a 91 dodge dakota and it has a high idle its a v6 3.9 but i cant not find out why it has a high idle

 

the most comon cause of a high idle is a vacum leak. finde the vacume leak stop the leak, and you will se what I mean.

 

actually....i would check the IAC valve first. A dirty IAC would be much more of a common cause in my opinion. Being a '91, its probably pretty dirty. Clean that, and the throttle body, and i bet your problem goes away.

 

oh yea! I forgot about the IAC I had that go bad on a jeep I owned. dodge uses a steper moter for that. somtimes they get dirty do to exsess carbon and oil coming from the pvc. they defanatly just quit working somtimes to. if you are lucky yours is just stuck open acting like a vacume leakleting all theat around the throtle plate. the lucky part I mean is maybe you can clean it and get it un stuck and it will start to work. i cant remember how much the IAX cost me for my jeep, but it wasn't much. just a few chees burgers.

 

WHAT IS THE IACVALVE

 

the iac valve is a little motor with a pointed end on it that screws into the back of the throttle body and yes they get dirty, and they do get stuck, i had to clean mine when my truck stopped idling on its own and it fixed the problem, but just go to autozone and ask them for it the can look it up, i want to say its like $20