Alright, sorry i didnt reply to the pm but i figured you would have gotten it by now.
If this started happening right after you replaced your fuel pump which im assuming by what you have posted.
Now, couple questions.
When you first turn the key on does the fuel pump fuse blow right away? Or do you hear the pump try to go the blows the fuse.
Here is the thing to do. Unplug your fuel pump. Turn the key on and see if the fuse blows. If it doesnt blow you have a problem with the wiring of the pump or the pump itself or something is shorting out on the pump side of the connector. If it still blows you know you have a wiring problem between your fuse box, to the relay, to the fuel pump. The power wire after the relay is the red with black, i cant recall what color the wire is on pin 3 of the relay. You would need to trace that back from the relay to the fuse panel 15 amp fuse. See if your wiring between your fuse panel and the fuse box got pinched, cut, rubbed through anywhere on the harness. Shouldnt be too hard. Maybe in the wheel well where it runs into car. Again check all for any rub marks, wear marks, cuts, and so on.
If this happened after the pump install then im almost certain you messed up the wiring to the pump or the pump is bad that you put in. I know on our b13's the original wires inside the tank like to fray and insulation come off. Make sure you didnt pinch the wire between the tank and the fuel pump/fuel level assembly that is bolted down with the ring. Depending on how you wired it up there could have been excess wire and might not have seen it get caught between the sharp edge of the tank and the assembly before bolting it down.
So try that stuff. Unplug the fuel pump, turn key on and if it doesnt blow you know where your problem lies. If it does, then you still know a general area of where the problem lies.
Good luck