My 86 B230F (248K) would not start very well either. (below about 15F) It would fire as I was cranking it but would just not keep running. If I kept cranking, it would eventually keep running as long as I kept the starter going for some time. (luckily the starter didn't fail)
Anyway I finally started to look into the problem last summer. I suspected the ECT. I broke open the harness up on the passenger side tower and ohmed it out. It read open. I went down to the sensor and ohmed it out and it was ok.
So I reconnected it and tried it again up above and it was ok also. WTF? (bad connection I guess)Well after that I could tell it was running too rich. I could smell it in the exhaust and my fuel mileage dropped. It also idled rough. I tried to lean it out by cranking the air mass meter but it ran out of adjustment. The idle did smooth out though.
And it now starts OK when it's really cold out.
Obviously there still is a problem with something (AMM, I think) but when the ECT circuit was open I think it was running in a default mode. Started and ran great when warm and got good mileage (about 26MPG) But when the ambient temp was below 15F, it was just hard to start. Ran OK after it started.
The engine harness is a piece of crap though. Lot's of bare wire here and there. I just put a new end on at the starter solenoid. (no crank condition)
Maybe next year I'll get the ambition to work on it again. Or if it leaves me sitting along side the road. LOL
Just sharing my experience with a similar sounding problem.
John