It sounds like a intake valve is not shutting all the way, but only sometimes and only at idle.
Some time it will accelerate on its own up to around 25mph without touching the throttle

no codes

 

MAybe a voltage issue?
do the 07 gen4 5.3s use a TAC module or does it just use the PCM?

 

anyone know if the throttle blade is supposed to jump around that much?

 

I'd look at 5V sensor supply to see if it's jumping around. Pull schematic to see all the sensors that are on the 5V ref circuit. You can disconnect sensors on 5V circuit to see if 1 is impacting the others. Basically try to isolate what influences the issue.

 

I found a schematic but it doesnt show what else is on the throttle curcuit

The IAt is jumping around like crazy but so far ive unplugged everything I can get to and it still does it.
Cant find a wiring diagram of ground locations either, everything I find is for 2007 classic body style and older

 

Well, after finding multiple sensors reading funky (at times) I checked all grounds and unplugged each sensor one at a time.
Nothing worked, tuned the VATS out of my spare ECM and swapped it out.... FIXED
I guess these ECM's can go bad after all...