Idle issue

[frei]

Hello I am new at this powerstroke/Diesel thing but here goes. I bought a very used 2000 F250 (220,000 miles) The truck has something called the Ban?? 6 gun. (not sure I can say the name) I don't know anything about this stuff. But here is the issue when I crank the truck to warm up it idles fine for a couple of minutes then it kicks into high not really idling faster. The truck has a straight pipe exhaust and you can hear the the turbo get real loud and fast. When I tap the gas it drops back down but after it sits a couple more it gets real fast again, tap the gas it drops down again but repeats. Is it the program or something else?
Thanks in advance for your help....
Also I could use any help on understanding this banks system.

[willholl79]

Sounds like the "fast idle" for warming up to me.

[frei]

That is what I am saying the idle is not any faster the turbo is in overdrive. Sounds like a jet out the exhaust.

[willholl79]

my 2001 does that when it is cold out. After it gets to normal temp it idles fine. There is some sort of valve that closes to reserculate exhaust or something. Sorry i'm not very technical. I only started noticing it when I straight piped it. I wouldn't worry.

[SCUFFY828]

yep thats normal exhaust back pressure valve shutting off when cold

[frei]

Good deal thanks for the info. Just a little scared about having a truck with this many miles.

Thanks
Frei

[redstroker_2002]

no big problem the trucks idle up to stay warm. and the noise is the valve behind the turbo that closes to warm cab and engine faster

[NCHornet]

This is part of the cold weather package and very normal. You may also hear a hissing sound and a lack of power until the engine comes up to temp.
NCHornet