Decided I'd make a new post as the other one was getting tough to read. (not to mention old!)

Engine is a 350, manual trans, '89 TPI. (essentially) No VATS.

First thing in the day, vehicle will start fine, and will run without problem until you turn it off. Whether it's run 10 seconds or 20 minutes, if you turn it off, it will NOT restart. Turns over fine, will not fire.

Has spark when problem occurs, injector feeds have 12V, but the injectors are not being commanded to pulse.

If I run a wire from the battery directly to the two injector 12V leads, it starts every time, no issue.

ALL ignition related connections have been removed, cleaned, and reassembled. De-pinned the ECM connectors, distributor, all grounds, etc. New Delco ignition module.

Swapping in a known good ECM with or without different PROM doesn't change anything.

Oddities: scanner never shows engine cranking RPM like it's supposed to. It didn't before the problem, so I somewhat ignore that. Two injectors ohm out at 13, the other 6 are all 16-17. Stock 350 injectors. Planned on replacing them anyways, but the plan is for the Ford ones, which will introduce more variables, which could make this problem more of a pain.

I don't have access to the vehicle now, I have someone that likes to play with this sort of stuff with the vehicle though, so we've been bouncing ideas off of each other.

The one thing that doesn't makes sense to me is why 12V directly from the battery solves whatever the issue is...why no injector pulse without that, when all the ECM is doing is grounding the circuit? Module signals ECM that engine is cranking, ECM grounds the injector circuit to fire the injectors.

Edit: ECM replacement "solved" the issue. Two injectors turned out not to work very well (tested) but they ohmed out right before. Hopefully combination of new injectors and ECM solves problem for good.