OK i have a 94 lude si with a conefilter and a little bit of throttle tuning when i took my old box filter off i just stuck that little hose (vacuum ?) onto the rod for the battery. For the past few months when i started my car it would experiance idle surge from 1500 to about 2500 rpms but as soon as the thermostat hits the first mark a quarter of the way up it would stop so i didnt worry to much about it.
However it has started doing it all the time no matter how long im driving and every now and then it will stop but then it just idles at 2grand i have no idea what it is and any suggestions would be greatly aprecciated. I do know that there are like 30 things that can cause idle surge thats why i gave more details about the problem to maybe narrow it down a little.

Also if you let off the gas in low rpm's it acts like it has really high compresion meaning that it starts slowing down alot faster than it used to and it just jerks forward (the car because it is slowing down) where as it used to be smooth it kinda acts like it would if the car was cold it even seems to have more power but idc because it is caused by something wrong with the car any help would be greatly appreciated and if you have anyother questions i will gladly answer them to the best of my ability.

sorry for the long post