Am I using the wrong power transistor with my ECU?

[90 GSX]

I have been trying to figure out a misfire and stutter on my car. I also get knock with 2g timing maps and base timing at 2*. High fuel trim is 99-101%. There is literally, and I mean literally nothing that has not been checked or changed on the car. I've come to the conclusion that the problem is igntion related and it probably due to the power transistor. The next paragraph will tell you why.

My car is a 90, but I am using a late 92- early 93 eprom ECU. The power transistor I have is the early 7 pin one that came on 90 and 91's. When I bought my ECU the guy told me it was from a 91, so I got a 91 PT and coil (the coils are interchangeable from 91-94). When all my efforts to fix the car failed, I checked the part number on the ECU for shits and giggles and it is a 7/92-5/93 ECU. Do I need the later 8 pin power transistor or are they interchangable? Did 92's and 93's come with different PT's? It makes sense to me that I have an igntion problem, all my other sensors are checked and verified, it has to be the PT. I read that the connector is the same but one has 7 pins and the other has 8.

Can I wire the 7 pin to work right? Is the 7 pin working right and is it not my problem? I have been driving the car with a 7 pin for a while and it works, but I not that well I am thinking.

Has anybody had experience with this?

EDIT:

I found this thread searching. http://www.dsmtuners.com/forums/showthread.php?t=126762&highlight=transistor

It doesn't quite answer all my questions though.

 

[bmwisthekey]

1st thing, the early 90 power transistor unit is a 5-pin, and the later 91-94 uses the 7pin power transistor, the other thing is the 90 coil pack uses a 4 pin square connector, the 91-94 coil pacs are a triangular ( 3 pin style).

Another thing is to verify that pins 6 and 14 were swapped on the ecu plug harness, these must be swapped when using a 91-94 ecu in a 90 car.

These are two really good sites
http://www.dsmchips.com/1990ecu.html

http://www.ecanfix.com/users/mdhamilton/ecuconversion.html