Mitsubishi Repair: Check Engine Light, head gasket, eclispe

Question
Hi! I have a 1997 Eclispe GS non turbo automatic ans its giving me some grief. I bought it in March of this year and I had a couple of things fixed on it already. A friend that works at the dealership said I had a leaky head gasket and a cracked exhaust manifold, which I just fixed about a month ago. While the shop I went to fixed all my problems they also changed my water pump and timing belt. Since Ive gotten it back now its running like garbage. I already took it back to him 3 times to get things checked out. Before I took it to the mechanic I told him about the idling going up and down all the time and they said it was normal. MY boyfriend who also has and eclispe but a gsx of the same year does not have this problem. He told me that it could be my idle air control motor but its not bad to fix. My main problem is that my check engine light keeps on coming on. The first time it went on they had to reset the computer. When I got it back I drove it about 60 miles (80 KM) and it came back on. So I brought it to him again and the same thing happened. He said he changed a faulty spark plug and i just picked it up yesturday and now its back on again when I went that same speed. Im so frustrated and I hope you can help me. Im sorry for it being a story but Im running out of ideas because I already paid a fortune. I dont have alot of money to be paying out for my car because Ima student. Please help! Oh ya I live in Vancouver Canada, do you know any good places for me to go?

Answer
Thuy,
It may be time to have someone else take a look at your car.  Your friend at the dealership should have been able to set your timing belt correctly.  I would recommend bringing your car to an AutoZone the next time your Check Engine Light (CEL) comes on.  I visited Vancouver about a year ago, and I think I remember seeing a couple AutoZones.  They can scan your car's computer for free and tell you why your computer continues to illuminate the CEL.  There is also a procedure you can do yourself to find out why your CEL comes on.  Read this for further information:
http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=8

An idle that continously goes up and down is not normal.  Your boyfriend was right when he assumed it could be the idle air control (IAC) motor, also called the Idle Speed Controller (ISC).  The symptom is commonly referred to as "idle surge".  It's pretty easy to check if the IAC is faulty, and not difficult to replace; though it can be expensive to get a new one.  You can check out this page for more information:
http://www.vfaq.com/FAQlocator-intake.html

Hopefully you'll be able to pin-point your problem and fix it cheaply.  If your friend at the dealership just isn't helping, find a new mechanic.  If you can find and fix the problem without your friend's help, then you can teach him something ;-)
Good luck!