Can anyone give me any idea of what might be causing my 12.7 detroit to idle rough? It seems to do good the rest of the time, but when it's idling...after just a couple of minutes, it really gets rough. I've tried kicking up the rpm's to 1000 and it does do a lot better, but then it will still start then rough idling again after some time.

I have some howe's fuel treatment, should I try that?

Thanks for any help,

Arky

could be injector. any reputable shop should be able to kookup hand held comp & plug in under dash to get reading on engine & tell you maybe in a min whats wrong.

I woke up last night with all the buzzers going and engine shutdown light on. Looked out and steam was coming up and water all over the place. My heart sank, as I thought it was blown head gasket. Nope, just a blown radiator hose. So while I'm getting it fixed at the garage, i ask the mechanic about the rough idling. He emphatically stated it is the shitty fuel that we are having to run in these trucks. According to him, a whole lot of people are having the same problem you and I have. I believe him too. Because I got some fuel at the QT in Atlanta yesterday and truck ran a lot smoother. So maybe they had some of the old fuel. I will be going back again to get more fuel from them.

thanks guys. Sorry I haven't had a chance to get back on CAD for a while. I generally use FlyingJ WIFI out on the road and for whatever reason, CAD has them blocked it seems.

I've found that if I bump the rpm's up to 1000, the truck will usually idle pretty smooth for a little while, then start the rough idling again. I've also learned that if I go and bump it up 1050 or 1100 rpm's, it seems to smooth out and stay smooth.

Thanks for the help!
Arky