I got a 1997 F350 with the 7.3 in it, when i first start it up, runs great until it warms up; then after that every time it idles rough and will bounce between 500 and 800RPM...and suggestions on what that might be?

 

How about a few basics, have to ask, you never know

Fuel filter fresh and clean screen b/w filter bowl and regulator?
Fuel pressure ok?
Recent oil change and level ok?
How many miles?
Previous work done?
Any check engine light?

Welcome to fte by the way!

 

218,525 miles, oil and fuel filter was changed about 300 miles ago, im not sure on the fuel pressure, no lights at all, and as far as im aware of there has been no work done to the engine other than basic maintance.

 

Welcome to FTE !

Unplug the ICP sensor and see if it changes. It's a sensor behind the A/C compressor on the head

Do you have are can get a scanner that you can see live data?

 

That could be a symtom of bad IPR O rings. Welcome!

 

I was thinking the same. Maybe a cracked oring, not completely destroyed yet..

 

yea, my brother checked it out with a snap-on scanner last night, the only code that came up was for a problem with the PCM, he said that will most likely need to be replaced, im gonna check my wire harness and plugs today, and ill check into those O rings, thanks

 

What was the code??

 

im not sure, forgot to write it down; just when of what my brother told me, hooked the scanner back up on it and nothing came up this time...

 

I'm thinking it's injector O-rings as. Do you have oil in your fuel (BLACK black fuel filter? I doubt the PCM is your problem to be honest... kinda one of those things that works or it don't. I have a '97 that idles bad and all-around runs like crap after it warms up. It fails cylinder contribution on #2, has got bad oil in fuel as well as oil consumption, even after injector O-rings, and I can kinda feel a "miss" of sorts. No excessive blowby so I can't blame the oil usage on that. ICP and IPR are reading great and everything else looks great. Pretty sure I've got a bad injector. But don't get worried just yet... injector O-rings aren't too bad and are pretty cheap compared to injectors or a PCM (still don't think that's a problem). Assuming you have adequate fuel, a temperature-related problem, especially if "warm" is a key factor, generally points to an oil problem.