This car would start and idle fine before I did work outlined in my original post. The problem was very sluggish acceleration followed by car stalling and refusing to restart for a few hours. I did not pull plugs at that time to see if they were wet. I did have approx 40 psi fuel pressure and spark.
When I did the work outlined in original post, I replaced boken studs and put an exhaust manifold from a '88 240 which relocated the O2 sensor to the exhaust manifold instead of on the Cat as it was originally located. I did not re-install the cat or front muffler on car, thinking the Cat may be plugged causeing the poor accleration.
When I tried to re-start car after completing work it would not start. If I pull plugs and dry car will fire but not run. Plugs get wet again.
Now after reading all of the very good post, I pulled 25 amp fuse, cleaned and re-installed. No difference. I then changed the ECU (was pink label) and replaced with a know good ECU from my '91 780 (b230 FT). Still no start.
Note - the 91 ECU is from turboed car where the 89 is normally aspirated.
I'm wondering if the problem might now be because I'm trying to start it with only the exhaust manifold on. As Art had originally pointed out, the leak on the exhaust manifold told the O2 sensor to dump more fuel. The differnce being that originally the exhaust leak was before the O2 sensor due to broken studs. Now the bigger exhaust leak is after the O2 sensor due to Cat and front muffler not being hooked up.
Going to re-install Cat and front muffler as soon as I deal with a couple of issues with it. I removed the original O2 sensor from Cat and can see the screen is pretty clean. Does a plugged Cat have that screen plugged or do they plug deeper inside?
Thanks again for all your thoughts/comments. Sorry for length of these friggin' post.