Engine bogs down and stops after six miles

I've had this problem four times with three vehicles. It was caused by the screen attached to the fuel pickup becoming plugged or it is collapsing. There's three clues. The first is the engine runs fine at first. The second is it only takes 5 - 10 minutes before it will run again, (as opposed to at least an hour for a failing sensor to cool down).

The third clue only applies to fuel injected engines with the fuel pressure regulator on the fuel rail on the engine. The stalling occurs most often when the highest volume of fuel is being pumped, which is during coasting. The engine will run okay at highway speeds or when accelerating.

The opposite occurs with carbureted engines like yours. There it is simply a matter of loss of volume, so the slower you drive, and with the least load on the engine, the longer it will run, until the gas is used up in the float bowl.