1996 454XL Stall Issue

Motor starts, idles, and RPMs beautifully, but stalls intermittently. Sometimes it runs for 30 seconds, sometimes it runs for 30 minutes. It doesn't matter what RPM it's at. It can be under no load at 2k rpm and just shuts off. Doesn't sputter, doesn't hesitate, doesn't throw any codes before stalling, just stalls. It's not running out of fuel or having a fuel delivery when it shuts off, it's definitely ignition related.

Is the likely culprit a disruption of 12v power (or ground) to the MEFI 1? And if so, what are some likely connections to check? Anything else that I should be looking at?

Fuel pressure is good, timing is good, plugs, wires, cap and rotor are brand new within the last week or so. Brand new injectors and rebuilt the TBI today, still stalling.

relay(s)

All about troubleshooting. Must be fuel or electrical. Might tackle electrical first and monitor voltage at selected places. Voltage to the coil when the engine stalls would be good to know. If voltage drops off there need to work upstream all the way to the ignition switch.

Check the large electrical connector for signs of corrosion. May just be an intermittently bad connection.