180sx no start

[92Blue180sx]

Hello all new to the nissan S13 game. Bought this gem a few months back.180 rain.jpg
Was driving home 2 weeks ago when I lost fuel pressure and car died. Checked fuel pump fuse and relays no problems there. Anticipating that it was the pump I did order and install a Walbro 255, pulling out what I think is a fuel pump from a R32 or R33. Checked the old pump with 12v and thats not the problem.
Checked for power at fuel pump plug and only getting 300mv not 12v. I am getting 12v at the relays as well. Running out of ideas any suggestions would be greatly appreciated. Need to get this pig running.