Engine RPM's bounce up and down
 

For the past month or so I have noticed when ever I come to a stop and push the clutch in the RPM's drop to about 650 and then go up to 850 and drop back down kinda like a spring until they reach idle and then idles fine. I have no clue why it is doing this all of the sudden, kinda is starting to worry me, anybody have an Idea?

...funny you should mention that.
 

..I've had three trucks come into the shop complaining about this sensation. Trucks never die, but the rpm dips down. It's all controlled electronically so not a whole lot we as techs can do right now. No flash or tsb relating to this to date.

I haven't worked on one this new yet so I don't know the system, but I would check for a tps and make sure it is set correctly.

Mine does the same thing, doesen't seem to hurt anything.

Dennis