When installing a Walbro 255lph pump in a 93 RX-7, does the output end of the pump push all the way up into the in-tank receptical until it sort of snaps into place, or is it just supposed to be pressed against the receptical's o-ring with a certain amount of pressure? Mine is currently just pushed up in there good and tight and secured with a hose clamp to the bracket assembly (it is a "generic" walbro pump, the bottom end not specifically made for the 3rd gen rx), and the car runs great except at WOT the engine cuts off completely at around 4,000 rpm like an invisible man next to me reaches over and turns off the key.

Any ideas or suggestions?

 

That sounds extreme at 4k. How are you set up? Stock boost on twins? Single? Injectors? Do you have a fuel pressure gauge?

Can you define a little better what you mean my cuts off completely? Is this only at WOT? Half open? Any gear?

 

I not sure but i think the stock pump has two speeds , check the voltage at the pump. I'll double check to make sure.
Looking at the wiring diagram now , it does have two speeds , check your fuel pump relays and the fuel pump resistor.
Fuel pump relay - left front engine compatment
Fuel pump relay (speed) - right front engine compartment
Fuel pump resistor- left rear engine compartment
I'm using a Microtech so I kinda went through this while wiring it up. Oh , I'm usin tha same pump myself , works well for me