Hi I have a 85 rx7 with a 12a that is on its last legs and will be taken out and swapped with a 13b rew. The fuel pump isn't kicking on when I turn the key to replace it i want to go with a pump that will also work with the 13b when it is eventually swapped in. Is there a pump that will work with both?

 

Not really. The 13b rew will require a custom setup with slosh cup and flow many times more psi (like a Walbro 255). The stock 12A pump needs around 4 psi and regulating a big pump would be hard plus take a regulator, The 13b rew will take a bigger supply and return lines also.

How long will the swap take? You can always get a cheap pump. Yes they have a tendency to go bad, but for a short time would get you by.

Are you sure it's the pump that has died and not the fuel cut relay under the dash by your right knee? If bad, they can be jumpered to work. Get the factory wiring diagrams here and test that cut relay. Foxed.ca

 

The swap is gonna take a while and is still in early stages I checked the fuses and i know that one is blown which I'm replacing tomorrow hopefully its as simple as that. I'll also check the relay tomorrow. Thank you for the help

 

well, for the sake of clarity, are you running the REW as an injected engine or are you running it with a carburetor?

 

it would be injected

 

then refer to what KansasCityREPU said.

 

If you wanted to do it once and future proof you could add a surge tank, a lift pump, and a high pressure pump. You'd then need to run a larger return line and add a return style regulator capable of reaching the ~2.5psi the Nikki needs. That ignores the larger feed you'll probably want for the REW.

I did this when I went blow-thru turbo with the carb, except I added the surge tank afterwards when I went EFI (alternative option to a slosh cup like KansasCityREPU mentioned). A Walbro 255 and similar pumps can certainly be regulated down to the low pressure a carb needs, but it's a little tough to find a regulator that is both a return style and can reach that low pressure while not spending more than a comparable high quality EFI pressure regulator would cost. You could run a return style regulator that'll bring it down to maybe 10psi, and then a deadhead regulator off of that until you swap in the new motor, although at that point you'd be much better off buying a temporary replacement carb pump for the 20-80 bucks or whatever they run.

You cannot install a pump that'll cover both carb and EFI without adding at minimum a return style regulator and larger return line. While I mentioned a couple options above for you to consider, I would not personally recommend them in substitution of a cheap carby pump for the time being. You'll have to replace something either way you do it - I'd rather replace a cheap pump and save the new lines and other work for when the car will be down for the engine swap.