Dying Regal

1991 Buick Regal, 3.1 engine, auto trans. Juice to Spark Plugs stops at random, killing the engine, usually within 5 minutes of starting. Rest of electrical system still seems to work okay, warning lights, etc, Sometimes it will start again, often not. Will die again soon if it does. Electronic speedometer & odometer don’t work. (90,000+? Miles) Everything else does, Great car otherwise!
I Ran codes, nothing. Replaced/tested: Coils, camshaft sensor, connector wire, computer, battery connections, ground wires, all plugins and wires I can find, fuses, relays, etc. Everyone gives me a different story.
I’ve disconnected the battery to reset the computer which often allows temporary relief. Also ran a ground wire from frame to Alternator to improve grounding. Still, nothing seems to solve the problem. Doesn’t seem to be a flood car but has been in a minor right front end accident that was home mechanic repaired. Any other ideas?