I noticed that when my car is just at idle it runs really smooth and the engine sounds fine. The problem I have is when i hit the gas it kinda hesitates and then rpms go up (not in gear). Then as the rpm goes down it goes to like 400rpm, then to 1000 and then back to normal idle. Also when the car is just at idle if I pump the brakes down the idle will again go up to 1000 and then back to normal. Anyone?