Firstfives.org

my '81 528i is not starting. I pulled the plugs (Bosch Pt) and they were very fouled. I replaced them with new Cu plugs, and have swapped out the following with used components that were good when removed:
AFM, ECU, Ignition control, fuel pressure regulator, master relay along with a new cap and rotor. The engine spins fine, I know I have fuel (at pressure) and spark, it just won't catch.

Any ideas on where to go next?

...tom

If it's got fuel and spark... Assuming timing is sort of close and the timing chain hasn't given up. You say the plugs were fouled, how so? Was it flooded? If that's the case, key off, pull off the ECU connection in the glove box, then crank it and try and start it. It should sputter and fire momentarly, burning off the excess fuel. Key off again, plug the ECU back in and you should be good to go, it will no longer be flooded. Check for spark first though, if it's got compression, spark at about the right time and fuel, it's gotta fire. (says the guy typing away at a computer hundreds or thousands of miles away, LOL)

That was it, it was flooded after many attempts to start it. After sitting for several hours it came back to life. I've never seen spark plugs fouled as badly as these were.

Noted Bosch pt, if acronym translates to Platinum Tip, consensus here is WR9 DS ( S for Silber). Platinums haven't gotten very good reviews, including don't even go there.