R32 Gtr Won't Start

[Truffles]

Another in the perpetual problems associated with my GTR in the last 6 months.

Story is; the stock fuel pump died and I replaced that with a bosch 040 and ran the direct wire to it and the car fired up again.

Ever since I've put this pump in I've had nothing but problems. If I sit the car for more than 12 hours or so it won't start. I believe it could be something to do with the priming or lack of. When I turn the key, I can hear the pump prime but I often have to wait and prime the pump 2 or 3 times before the car will eventually start again.

Any insight into what this problem is caused by would be very helpful!