Here is another resource for you:
https://www.e46fanatics.com/threads/e46-no-start-–-list-of-possible-causes.1011677/
While it is for the E46, the concepts are all the same on your E36/8
Thanks for the reply. I've been scouring E36-E46 threads and documents for the last couple weeks. But in my case, I found the issue, and it's kind of a DUH moment. I'll recap in case it helps someone else in the future ('99 NA coupe with m52b28tu).
tl;dr: It was a blown fuse 26 the whole time...charts and diagrams are misleading.
My coupe was molested by the previous 6+ owners, so I knew it was unique when I bought it. I took out the center console to troubleshoot and eventually revamp 90% of the stereo system. After driving around for a year with the center console removed, my buddy and I reinstalled it...and bam! Strong crank, no start. There was no indication of issues with running prior to this. Here's what the cluster looked like:
This is where I started to chase symptoms instead of the problem. The tach didn't bounce when I tried to start it, so I immediately thought CPS. Swapped one in, still no start. So the temp gauge pegging right made me think faulty temp sensor cueing the DME to not start the car when it was "overheating". It was about this time that I started swapping fuses too. I pulled every fuse and swapped all of the "relevant" ones (FP wasn't priming, couldn't communicate with DME through 16 or 20-pin...), but I didn't find anything blown. I tested power to FP and all "relevant" relays and verified power to fuses but not at FP relay or FP itself. Checked fusible link, and it was good too. Had power to non essentials like lights, seats, windows, etc.
Swapped the coolant temp sensor, tried another CPS, still no go. I was suspecting DME corruption for some reason without a hint to causation (maybe shorting something with the console reinstall...). I began pursuing the no comms with DME hoping that I could get a resolve so I could get codes. In doing so, I found
this thread talking about fuse 26 controlling the 20-pin. On my fuse box it says 26 is ABS/ASC and I had no indication those things weren't working. On the wiring diagram, it shows DME and DataLink along with other things like cruise control interface (ASC) and reverse light (plus some other little things). Anywho, rechecked that fuse and sure as sh!t it was blown. Replaced it, fired right up, and now I can communicate with the DME on both 20-pin and 16-pin.
I think the logic is that if your ABS isn't working, what better way to notify you than to disable the car...but IMO it should disable the car while still retaining the communication to the DME so codes can be pulled. Don't know the cause of the fuse blowing (yet) but I swapped my original CPS back in and it still fires. Going for a drive today! Hope this helps someone...
