1991 Mitsubishi 3000GT only running on 4 cylinders

OK, I have do a little bit of research already, but I know that it can be dangerous if I don't know what I am doing. Basically, two of my cylinders aren't firing. I checked the coil pack (by switching it with another working one in the car) but the new one didn't spark either. I got out my trusty wire tester and saw that there was con constant stream of power going into and leaving the coil pack, but it wasn't fluttering (the power for the other coil packs 'flutter' in time with the spark.) So, I also checked the ECM (under the center console behind stereo) and it looked like a couple of the capacitors possibly could have leaked, either that, or the board is just a little rusty (the car did sit for 6 years with a slipped timing belt before I got it). The car does run and drive, but not very well. I would really feel much safer if the car ran on all 6 instead of just 4 cylinders. My thought is to just replace the ECM, but I don't want to spend that much money just to find out that the problem was something else. Other than those 2 cylinders not getting spark, the car is basically fine. What suggestions could you offer?