[sammyg2]

I guess I could see how that might make sense, but it is without merit from a physics standpoint.

At sea level we have about 14.7 pounds per square inch pushing down on us, on the stuff around us, and on the fuel.
The vane pump (positive displacement) creates a lower than atmospheric pressure in the suction line.
If the pressure in the suction line is lower that 14.7 absolute (zero gauge), then the diesel fuel will be pushed up into the suction pipe in an effort to equalize. Higher pressure always wants to go to lower pressure.
If the pressure in the suction pipe is low enough, the fuel will be pushed all the way up to the pump where it will be pressurized and sent on it's way. We call that suction but there is no thing really, it's a layman's term used to describe head pressure below atmospheric. If the pressure at the suction of the pump is not low enough for the atmosphere to push the fuel all the way up to the pump it will not take suction. The ability of a pump to be able to create sufficient suction determines if it needs to be primed or not and that is inherent in the particular design.
If I understand your description, the suction line is 4 feet long and the pump has to create 4 feet of lift. That is not hard for a vane pump at all unless it is completely worn out and the internal clearances are shot.

The head pressure of water at sea level is about 33 feet or so, haven't looked that one up in a while. Might be 34 feet.
So if a pump was perfect and could create absolute vacuum (which they can't), and it could lift a column of water 33 feet. The most efficient pumps at doing that I work with coincidentally are vane pumps in vacuum service (again, not a scientific term but slang). Diesel fuel has a specific gravity lower than water but pump engineers always use water as a measure of performance characteristics and then divide by specific gravity for actual instead of theoretical. Don't ask me why, we just do. I guess it's easier to teach the students that way.

Pumps can build up enormous discharge pressure so they can push a column of liquid much higher than they can pull it. Similar to a Porsche engine (wink wink). A normally aspirated engine is reliant on atmospheric pressure to "push" air into the cylinders on the suction stroke. A turbo doesn't, because it can build positive gauge pressure which is cumulative with atmospheric. 1 bar of boost is actually two atmospheres of pressure or almost 30 PSIA.

You seem to be confusing two different principles. The drinking straw thing is all about surface tension. Totally different application of theory.