Well . . just for "giggles" - your Electric fuel pump is "between the mechanical pump and your carb" ?
The electric fuel pump - - should be , back close to u'r fuel tank ; and , thus pump forward , towards the engine. Some of those elec. fuel pumps , don't work very well = having too "suck gas" that far.
I had this very same 'problem - on a 79 Ford truck' ; that I fought for over a year. I'd pull over and remove the TOP of the 2bbl carb . . . . the float chamber, would be 'dry' .
I was using those "small clear fuel filters" , too see if my fuel line was running dry . I fought this "condition" for a long time (even replacing that carb with a brand New 2bbl stock carb) .
Turns out - - - I would keep changing out - - - those clear fuel filters ; but never checked the "stock fuel filter" (that filter , that "screws-into the carb float chamber" ).
See , what I'm saying - - - I would change ONE fuel filter & not even check any other "Fuel Filters" ............................... that stock , screw-in Motorcraft fuel filter , was my "problem" .
So, make sure too "not focus" , on just one issue (meaning = Check all your fuel filters ) . What carb are you using on your 250 engine ? ?
jim
I don’t believe this carburetor has a separate filter. The valve cover does have baffles that the PCV go in between.
The gas line does not leak gas at the pump, it allows air to escape (not making a seal) if that makes sense?
