ZorroZ

I'm about ready to throw a piston through the firewall if you know what I mean. My car decided to play this game where it will idle alright for a day and then idle like crap for the next week. Basically this is what's up. The car goes through a rough cold start up. Around 4 seconds holding the key in the start position before it will start. Then after it starts it idles around 5 or 6oo rpms for maybe 2 or 3 seconds. Then it shoots up to 1000 rpms for another 10 seconds while the engine is warming up. After the 10 seconds it shoots back down to 500 rpms for 4 seconds, then up to 800 for 4 seconds then back to 500 for 4 seconds. It just keeps doing to 500 to 800 over and over if the car is just sitting there running. The car drives fine as far as cruising down the highway going 60 mph. If I the car is just sitting there idling and I push the accelerator to the floor really quick it will make this "air sucking" sound for a split second before it responds. So it's pedal to floor - engine goes quiet - intake sucks in air - engines rpms go as high as they should with the car sitting in neutral with foot on accelator all the way to ground Ok, help!