It was the IGNITION SWITCH!
Last summer on a trip we got more and more frequent stalls and almost were stranded on I-80 with a dead engine because of this:
The contacts in the ignition switch were corroded and brittle; when turned on they gradually lost their ability to conduct and the switch got hotter and hotter.
Thankfully, at one stall stop in West Des Moines we picked up a switch and an ignition module thinking it might be one or the other. It was the switch. I changed it out at the next interchange and suddenly those mysterious stall-outs went away.
This is one reason I love my '83. It keeps on challenging my brain.
Airstream OCD...there is no cure!
1983 Classic 310 Motorhome.