'92 Coachman Chugs & Stalls Cold Gas to Fix - Another Way?

SMPLMN, that does not quite match what I've seen when the fuel pump start running hot. I do think that if yours is original, it should be replaced. But I'd be suspect of the ignition coil in your case, due to the pattern/timing of your symptoms and because it idles even after your symptoms start. If your plugs have too much gap, that can also make the ignition coil run hot, and when it gets hot resistance increases and spark gets weaker.