When I accelerate from a stop my RPM's shoot up too around 4500, before it kicks down to a normal range. If take my foot of the gas momentarily then accelerator again it helps. I have also noticed that my amp gage is fluctuating again. I just changed the alternator 2 weeks ago. There is no check engine light coming on. I did find that the plug on the MAF sensor was loose. I reconnected it. That seemed to make it go away for a little bit then it started happening again.