No spark on #2 move coils around, still nothing on #2.?

[Fillbilly]

Can anybody give me some guidance here? I can't figure out why I have no spark on #2. If it sits for a while it will run fine for about 2 miles, then it runs on 3 cylinders after that. It happened once so I replaced the coil with a cheap one and it fixed the problem. The same thing started happening again so I ordered 4 bav auto coils and noticed that I had a loose plug wire.. oh well I put them on anyway. Car ran great for a few hundred miles now cylinder #2 has no spark again. So I swapped coils around and still #2 is dead. Swapped wires, still #2. Any ideas I how to troubleshoot or resolve this would be a huge help. Thanks

[Fillbilly]

Sorry, this is on a '91 e30 318is m42.

[AndrewBird]

Pull the DME and look for burning. One of the transistors for the coil packs might be dying.

Mine completely fried:

[Fillbilly]

Is it possible to replace the transistor or should I just get a whole new dme?

[roguetoaster]

I'm sure that you could find the right part if you looked around enough, but it's probably easier to just get another DME.

[oldmann]

I see your in Michigan, check the connector leading to the #2 coil. Look for corrosion in the plug.
Also meter #1 coil for voltage and grounds and compare with #2.
Intermittent issues like this often lead back to bad wiring/grounds.

Sent from my SM-G900P using Tapatalk

[Fillbilly]

Is there a certain voltage I'm looking for? Or just that it matches the other coils?

[Fillbilly]

The original did not look fried at all but I have not had time to put a meter on it yet. I did change out the DME with no luck. it is from an e36 m42 instead of an e30 m42 but it started up and still had the same no spark on #2. I guess I have to chase wires now