I had noticed recently while driving a sensation like my car was "surging" but didnt pay it much mind until yesterday. I was outside in the car and if i hold the rpms steady anywhere above idle it will drop 500rpms then rev back up while maintaining constant pedal pressure. The same thing happens while driving and a constant speed while cruising just not as noticeable. The car revs up ok and accelerates good it only seems affected at a constant pedal pressure. Any Ideas?