Read up on something called idle surge. You'll be amazed on how many posts you'll find. These cars are prone for it if you dont know already.

James

Check all hose and vacuum line connections.......vacuum leaks cause nasty idling problems.

mine was doing the same thing, replaced the ISC motor with a new one and its back to normal. not sure if thats your problem or not but it might help to replace anyway

Yea same here, check your ISC and hoses. It is amazing how one leak in your lines will make a world of difference. But yea I changed my ISC and all my vacuum lines and it fixed my idle surge, just be glad you don't live in a state that goes from -10 to 110 with 100 plus humidity.

http://www.dsm.org/how-tos/tttt/tttt3.html

http://vfaq.com/mods/BISS-1G.html

Thanks to everyone who gave me advice i forgot to mention that i need to replace my intake manifold gasket and i have a brand new one i just havent had the time to look to see if it is something i can do by myself or not. But i am trying to get that on before getting it tuned this weekend. I also will look into the ISC and check everything out. But does anyone think that the gasket could be causing my idiling problem? The guy i bought the car from said yeah when i spray a can of ether on there she purrs for about 30 secs to a minute so he was trying to say thats what was causing it... Any suggestions? Thanks
- Brent

If the intake gasket is blown it will cause it to idle bad because it is sucking unmeasured air. Just like if you had a bad boost leak which is pretty much what it is. So i would replace it and check your isc and vacuum lines and do a boost leak since it has a front mount on it

Yeah so it could be a vac leak, boost leak, intake mainfold gasket, and idle surge? wow have a lot of work before she gets tuned this weekend then. Well heres that video i promised maybe it will help. sorry about the shaky camera was filmed with a digital camera but it gets the job done..

http://www.youtube.com/watch?v=KK_TClyU5bM

Let me know what you think.
Thanks

If any one got a chance to view how it was idiling in the video i took and have any advice on that let me know. Thanks in advance.
- Brent

yep, its your isc thats causing the problem! it happened to my eclipse gst. i switched it out with another isc from a hyundai car that i found at the junkyard. switched it out and everything was fine!

some of the parts are interchangable with other mitsubishi cars too.

Ok so i have called and lined up 2 junkyards that have 3 or more talons/eclipses and I'm going to swap out the isc tomorrow. But i still need some help with the fact that when i push down the gas pedal more than an inch like if i go to rev it up during warm up it dies down when i go more than like half way. It happens in gear too, not just in neutral and i pretty much cant get it over like 25 mph.. So does anyone have any advice S-AFC II wise for me? Or do you think its something like the ecu? Only reason im saying the afc2 is because i think my little brother cycled through it and was hitting random settings. (mom told me she found him in the car when she came home from work so i wouldn't doubt that happening) Thanks for all the help up to this point guys.

That sounds like a boost leak. If you press on the gas and its blowing out measured air, and doesn't know what the hell is going on because its being lost. Check you hard pipes and the clamps for them. Make sure everything is all tight. A boost leak test would be the best thing, but you would have to build one and have an air compressor. That idle sounds crazy, it jumps up, sorda stays and then rises to 2k before going back down. Sounds nuts. I have idle surge, but no boost leaks and mine goes away after sitting. Yours sound like a boost leak symptom for the fact that it dies after giving gas. I would check that out before putting in an ISC. Fix what you have to on these cars. The old saying holds true for these f*ckers, if it ain't broke, don't fix it.

James

Yeah well i got some work to do on her this weekend for sure. I am just having the worst luck trying to find someone out my way to help me fix her. I can do the small tune ups and the bolt on's but I've been trying to find a good tuning shop that will also through in my intake manifold gasket. I called that mitsu dealership down the road from me and the second i heard $250 just for the labor i was like forget that. SO if anyone is out my way (pittsburgh, washington county, 15367) please help out a fellow dsmer with some advice to a good mechanic. Thanks again.
-Brent