w124 '88 300TE fuel delivery problem

[rjk]

I'm having what I think is a fuel delivery problem with my daughter's wagon. The tank capacity states 19+/- gals. but when it has used only about 15 gals. it will buck and stall as if it is starving for fuel. This assumption is supported by the following, if I let it run until it stalls out before I fill the tank, it will take a few tries (cranking) before, what I assume, is the air getting purged from the system and the engine finally catching and starting. It will then run fine until another 14-15 gals have been used. I am assuming (I know, a dangerous thing to do) I have used 15 gals. because that is all I can fit in at the filling station. This would theoretically leave about 4 gallons still in the tank but unavailable for some reason. My low fuel indicator light never comes on except when I crank the car to start it.

Volvos have a history of cracked hoses between the prepump and the tank outlet which can exhibit symptoms similar to what I am experiencing here. Is it a likely scenario for the Benz? I know my pre-pump is functioning but haven't checked the main pump yet. Is there a quick/easy way to do this? Where should I connect? I do have a gauge with a bypass valve for checking flow.

Should I be looking at anything else before I pull the sender/pickup unit?

Any advice is appreciated.

K