Time to get started 4.8 to 5.3

Even though the problem I had is slightly(or entirely) different from yours, here's something my truck did. I would take off driving with the high idle. Then I would stop, with the truck in drive, and sit there for about 20 seconds. The idle would then go down to where it was supposed to be and remain there until I shut the truck off. Once I restarted the truck, the high idle would return.

If your truck does the same, then you may have the IAC hanging open like myself. If not, then good luck! I tried...


Lastly, did you double check all your grounds? I know i missed one when I swapped my 6.0. It was one on the back of the block(didn't seem to affect anything though).

I will try that tomorrow I am going to have the Exhaust put on it.

Drove the truck today had the exhaust put on boy did I mess up with the mufflers way to loud way. Used pipes violators they are coming back off tomorrow. Tried driving it with the IAC plugged did not help any. Truck runs very good just need to get the idle fixed.

No new tune yesterday. Sure is nice to drive it finely. One thing is bugging me. Some of the guys on here still say un-mitered air coming in if so way would it idle fine with the IAC unplugged.

One more fast update. Zero done kids keeping me from working on anything. Hope to put smoke to it tonight.

I just read this whole thing dont have an answer for you but good luck i want to see how this turns out hope you fix it soon

Trying to get a way to data log it now. That will tell us a lot. Smoke did not tell us anything other than no leaks.

If you're bored, try plugging the hole in the throttle blade and see if that helps. I'm not sure if that would bring the idle far enough down from 2k though.

Did that. First it dropped a little and then went right back to 2000

Quote:

---

Originally Posted by 3DTIM

OK Put on a loner TB today same thing. Unplugged idle is fine plugged in and it jumps to 2000.

---

The "loner TB" had a used IAC valve, not your new one, right?