After much thought... I agree now that the diameter does not effect pressure or load on the pump.

Pressure is pressure. I was confusing the idea of accelerationg having an effect on the fuel vs. diamter having the effect.

To clarify my thinking. The harder the car launches, the higher pressure will be seen at the pump right?

But I now see that it has nothing to do with the diameter.

I kept thinking that the fuel column weight would be applied directly to the fuel pump vain (vane? sp?)

When I thought about the pump more specifically, I realized that the orfice size of the pump wasn't changing when the fuel line size changed. So if the same area of pressure from the pump port orfice wasn't changing (meaning area), how could the diameter of the fuel line possibly effect the pump?!?

That opened my eyes to the concept of diameter not effecting the force.

Thanks guys for taking time to explain. I know it must be frustrating some days, but at least rest knowing that you've opened another's eyes on the subject.

On more person now to fight old wive's tales about fuel line diameter!

Now I see why I got an "A" in statics, and only got a "B-" in fluids.