Mitsubishi Repair: 92 colt idle surging, colt vista, north kc

Question
I bought a this wonderful little 1992 colt vista AWD 2.4Ltr a year ago.  I had to convert the A/C and put tires on it and it ran finw for a bout six months.  Of course my six months went from 169875 miles to 192000 miles, so I was driving it alot.  It as a 5 speed and I had to put a new clutch in it. spent 980$ wich is about what I bought it for.  Then slowly over the past summer the Idle has gone from rought to a consistant surging from 1K rpms to 1.8K rpms.  I replaced the ECU under the dash, the TPS, all oil, fuel, and air filters.  Also in the morning I have to unplug the electrical sensor at the top left end of the head cover to get it to start, and plug it back in the rest of the day after it warms up.  I drove about 120 miles to a Mitsubushi shop in North KC and they ran a full diag on it and told me I needed about 3200$ of work on it, but The idle was from the Engine Idle Speed Conrtol Motor.  I really dont know what it does or how, but I do know the part costs anywhere from 700$ to 1000$ from the dealer, if they have it. I found one in a pull it lot but it was for a 1.8 Ltr.  Any suggestions on if this can be cleaned, rebuilt at home or where I can get one?  Thank you, very much.

Answer
Mark: Places to check for that Engine Idle Speed Control Motor would be at a junk yard. The dealership are very costly on those kinds of parts. I had a car which was old but still running good, a sensor went out on it and that crazy sensor cost more than the blue book on the car. So I found the part I needed at a junk yard. You need to try to find a repair manual for your car, might have to get one off line. But that would help you understand what some of these sensors do. Give me a car built before computers and sensors. So try a junk yard, I don't know if that can be rebuilt or not. But I wonder why not... well I will look into that for you. You might check around on the net, you might be able to find one there or maybe even ebay. I have found some odd things on ebay. Still there has to be cars like your's junked someplace. As I said you might check the net, as there are all kinds of junk yards on it and they would be willing to send the part to you. I know the dealerships are always so costly and they really don't act like they want to work with you on the cost. But I will save your email and check around too. Unplugged the sensors to get the car to start can be a pain but if you like driving the car for now you might have to keep doing that. Hope this helps and good luck! Linda