Yes, I believe it should hum like a small motor. I also believe your fuel filter may be clogged. You might want to see if you can blow through both the filter and that hose.
I would imagine that the fuel pump most likely has bushings or bearings on each end of the armature. If they are worn, the armature will drag and cause it not to spin. Then again, if it has brushes in it if they are worn out then the voltage is not passing all the way through it. Is the any way you can get that fuel pump apart and also get it back together?
Autozone has a fuel pump for $243
Also the fuel filter for $24
The part number is XXXXX according to autozone for the fuel pump.
I searched Google and found that Amazon has it for $177.
Pelican has the Bosch fuel pumps for $234 and $232 for the turbo and non-turbo.
Fuel Pump, 944 Turbo, 944 (1983-88), 924S (1987-88), Each Brand: Bosch [More Info]
Fuel Pump, 944 (1988), 944S/S2 (1987-91), 968 (1992-95), Each Brand: Bosch [More Info]