[Rixson]

So your scenario sounds almost exactly like a scenario that I had with our Beaver. It has a CAT 3126 and a whole different fuel supply system, but... After many attempts like all of those suggested above, it actually ended up being a sensor on the engine that tracks the amount of fuel flow.... It's ironic this happened when we were also very low on fuel and coming down a hill that we had just climbed....much like you describe in your situation..
My point is, I spent days trying to solve what I thought was a fuel supply problem, and it turned out to be an electrical problem ultimately...