sounds like a vacume leak in betwenthe intake mani and throttle body and also check to make surethethrottle body gasket is correct. if you wanna check you can get a can of intake cleaner while the car is running and spray it where the 2 parts mate all the way around if the idle drops or sputters then there is your problem. hope this helps oh and if this is the problem then you might want to open up that idle screw if its closed or turned down to low it will make starting a pain.