Will not stay running

So, this was a barn find vehicle bodies in great shape low miles for being 30 years old. It needed a battery and after going through it realized it needed rear calipers as they were stuck. Replace calipers and pads. The vehicle wouldn't stay running it would start and die figured it was from sitting in bad gas so drained fuel, new added and changed the filter.
Start it up fine and ran. We went to test drive after the brakes would not start would only start and then die. Fuel pump was replaced by somebody else in the last couple of years could tell because it wasn't as rusted as the collar. Thought that due to the filter being very clogged to where you can barely blow any air through it that maybe it burnt out the pump. Got a new pump and put it in. If I used ether the car would stay running but the injectors would shut off. Verified that the injectors were cycling by using a noid, but not fire after about 2 seconds. Replaced all the injectors and still having issues. The fuel pump relay and the shut off relay all are good and have tried bypassing and still the same start and then dies. Fuel pressure sensor good,
So, the big question is what would allow the car to start momentarily and then kill the power to the injectors?
Like I mentioned before, if I give it fuel through the carburetor or use ether the car will stay running so it's not losing spark plug spark it's just losing the power to the injectors to inject fuel.
Is this a ECU problem?
Thanks