1990 runs rich, stalls sometimes

My ecm isn't flashing at all, how would I go about this?

Professional quality scanner is required .. It is best to do some testing 'before' buying and replacing ANY parts! However - IF enough parts are installed - that has a good chance of fixing the problem. Good luck with it!

with my car, you have to count the blinks of the check engine light then find the blinks on the cheat sheet, my check engine light isn't blinking, any way to retrieve anything stored by using a paper clip and jumping across terminals? I sort of remember that one for a different condition that persisted

https://www.youtube.com/watch?v=TRIpM1awD8s

Well that will flash any existing trouble codes - what I am referring to is much more involved testing.

Thank you very much for that info. I bought the car used about 2 1/2 years ago, so I don't know when it was last tuned up.