my mate had a prob with his pump and broke down loads of times, but being in the AA and at 1am plus he always called them, i dropped the tank and pump a S/H pump in and it still wouldn't go, turned out that the fuel cut off switch was playing up, even when i tested the circuit with my meter it read like there was no brake in it but once i switched the cut off, off then back on, no probs, think the pump was fucked anyway but fingers crossed no problem since
some times you only need to take the sender plug off and put it back on if the pump dont prime up.
oh, as for the fuel gauge, even if you take the clocks out it will still show the amount of fuel that you have, dunno why but thats the way it works
hope you get it sorted mate