I think your diagnosis is correct. As well as the type of engine.
I think the drivetrain was supplied by DSM (Diamond Star Motors).

I have a 90 laser with the 2.0l, I had the standard cracks in the exhaust manifold so I started it and warmed it up then proceeded to weld the cracks shut.
After I was done welding the cracks I couldn't get it started, that's when I started kicking myself for not disconnecting the battery...

Sometime we make expensive mistakes...