Another e30 at my house...

#21

are you sure the main relay is getting power? There is a small wire running in parallel to the main battery cable. If it is not powered, then the car will crank but not start. I had this wire come off my kill switch once and it was frustrating to track down …
cheers,
bruce

#22

Have you checked the carnkshaft position sensor. They usually are good or bad but sometimes they can be intermittent. Per the "101 Performance Projects for your BMW 3 Series" book Wayne Dempsey cliams "If it fails or works intermittently, the engine will barely run or not start at all" These sound like your symptoms.

Don

#23

I’ve tried the CPS from the race car (along with lots of other parts
from the race car). It will pop and sputter occasionally, but still refuses
to run. I’m going to pull the injector/fuel rail and check that out when
I get a chance.

Steven