Small update… i got in a new main relay just to see if that’d fix it, and also because the “main relay” that was in the car was not an actual OEM Mazda relay… it wound up being a fan relay for a Honda that happens to have the exact same plug… so now i have a factory relay in place. Still doesn’t run without the jumper though. So, my next step is to source a 1994 ECU and see if that fixes it… my ‘scary’ thought though is that something else may have caused an ECU failure, and i’m not really wanting to hurt another ECU in the meantime. So i dunno. Again, runs fine with the jumper.
Oh well. ‘sigh’