i converted to carb from tpi. i got a mechanical fuel pump. i put on the block. there is an in and out and one in the middle. what the one in the middle for. ive had the pump for years brand new. it was for a 76 monte carlo 400.

 

If the "in" and "out" are 3/8", and the "middle" is 5/16", the middle is for fuel return.

 

can you just dissconnect your tpi pump by pulling the fuse then hooking up the mechanical pump will it be able to pump through the tpi pump or will i have to fig something out i just got done swapping from tpi to carb

 

You will have to remove the TPI pump from the tank and find a carb sending unit as you won't be able to pull fuel through the electric in-tank pump. That said, I would personally keep your TPI pump in the tank, put a regulator on the fuel line to pull the pressure down to 6.5psi and not use the mechanical pump at all.

 

Or, convert the EFI pickup to a carb type. There is a sticky about it in the Carburetor forum.

But, as stated, I'd also keep the in-tank pump and use a return style regulator.

 

AND - if you go this route, you'll have to use a return-style fuel pressure regulator like the Mallory 4309. And 6.5 psi is still too much, you want 5.5 or under depending on what carb.

Going this route means a blockoff plate for the mechanical pump, and get rid of it. But it's easier than dropping the tank!

 

Agreed. If it's not "in" or "out", it's return. And dropping the tank is awful. So if you can and are willing to make do with a return style regulator, then I definitely would.

 

k thank you guys for all the info i went with a regulator didnt feel like dropping the tank but i went to crank it over and the fuel pump didnt prime i have the fuse and relay hooked up i was wondering if there is a ground in the old wiring harness that i may have missed the whole harness is still hooked up any help would be awsome thanks guys