Classic/Antique Car Repair: fuel pump, fuel pumps, delivery tube

Question
I own an 82 vette,fuel pump runs but does not pump fuel.What is the problem?

Answer
The in tank fuel pumps have been known to separate from the fuel delivery tube in the tank. The other possibility other than a defective fuel pump is a plugged inlet fuel filter in the tank. This is a sock on the inlet pick up tube that is supposed to be self cleaning.
Brad