Issue with ignition system.

[Kaizen Zungu]

Good day. I have a BMW e36 316i.
The issue I am dealing with us that only 3 out of the 4 spark plugs are firing. Like any rational thinking person, I changed the spark plugs, but the problem still persisted. I was able to test the ignition cables and I found that they are perfectly fine.
My coil pack on the other hand was suffering from drastic overheating, so I bought a brand new coil pack, but the problem of only having 3 spark plugs firing persisted.. What could be possibly wrong? Might I need to just buy a new computer for the car?
Because it also doesn't respond to any diagnostic tests.
This started a month after having put a new m43 engine on the car, which is the exact engine type the car uses.
Please help me out, this car is my baby, my love, my beastly e36.

 

[Donovan2412]

I think perhaps another DME (Computer) is needed.

What do you mean by "Because it also doesn't respond to any diagnostic tests" ? is the computer not able to connect or is it showing no faults?

 

[Kaizen Zungu]

I think perhaps another DME (Computer) is needed.

What do you mean by "Because it also doesn't respond to any diagnostic tests" ? is the computer not able to connect or is it showing no faults?

It completely fails at connecting; it has never even gone as far as showing faults. it is as if the car's computer is brain dead, but the weird and frustrating thing is that the car starts fine, no 'check engine light' turning on. when the car is running, you can immediately feel that only 3 spark plugs are firing, and one is just not receiving any electrical input from the coil pack. I tested the ignition coil pack on a different 316i and it worked like a charm. The wiring loom is intact, no cut or loose wires.
From all that I have noted from the car, I feel as if the issue is with the ECU.
Which is why I am in desperate need of advice from another E36 enthusiast.