Ok so for the past year or so when i start my engine cold it sits at about 1200 to 1500 rpm's for 5 sec or so and then drops to 700 rpm's and then that kills it almost everytime. untill the engine warms up it will most likely die or drive really ruff. it used to stay at high rpm's for a couple min till it warmed up enough. I hear it could be a vacumm line. or iv also heard it could be the IAC valve going bad. any ideas? Thanks.