Mitsubishi Repair: 3000GT Rough Idle, Loss of Power, running rich, spark plug wires, worn piston rings

Question
I have a 1991 Mitsu 3000gt vr4 Over the winter on a cold night I started it up and was driving up a very steep hill realitivly fast when suddenly the vehicle started running rough lost a substancial amount of power and is blowing a lot of fuel out the exhaust.  I originally assumed it was timing since I have had the timing slip in the past so I am doing the 60k service.  I have done all of it exept the plugs and wires on the rear bank.  I have removed one plug at a time running the engine and found that the idle gets smoother when I remove the two plugs for the cylinders that are oposite of each other 1 and 4. If you have any ideas I am open to give them a try.  My current thought is that I have bent a valve.  
Thanks in advance.
Garth

Answer
Garth,
If you lost power and started blowing out lots of fuel, that means one of your cylinders stopped firing.  That can be due to numerous things: bad spark plugs, bad spark plug wires, malfunctioning ignition coil, or even a bent valve or worn piston ring.  Consider replacing your fuel filter if you haven't done so within the past 2 years.  Be sure to replace all of your spark plugs and wires.  The rear bank is just as important as the front.

I would recommend first getting a compression check to be sure your cylinder compression is to spec.  If you have any bent valve or worn piston rings, a compression check may help reveal this.  

Since your spark is overall controlled by your car's computer, that is worth checking out too.  Read this article for further information:
http://www.90gsx.com/eclipse/cap/caps.htm

If your ECU looks damaged, this can cause this malfunctioning that you're seeing.  Check the items I've suggested and hopefully it'll get you closer to pinpointing your problem area.
Good luck!