Looking for injector advice

I've got a '91 XJ, 4.0/AW4/231. I'm swapping in the same drivetrain from a '96. I know all of the OBD-I/OBD-II issues (thanks go out to all those that gave me advice and help-you know who you are), and have that part figured out (for the most part :shhh: ) but I need to know about the injectors.

They are rated differently (~21 lb./hr for the '91, ~24 lb./hr for the '96) according to what I've read. If I use the FPR, pump, and injectors on my OBD-I system, will I have issues? The main reason I want to use the '96 injectors is that all of the stuff on my '91 is about shot, and everything from the '96 is in great shape.

Can anyone help me out here?

The problem is going to be fuel pressure--96 injectors operate at 49 psi,your 91 at 39 psi.

If you could raise the pressure to the higher level,then the 96 injectors should work.
MAYBE-swap to a 96 internal regulated pump,block the return line--see what happens.
Just thinking out loud---
Wayne

PS-- a new set of the 39 psi injectors from 5.o motorsports is less than a new fuel pump---best of both worlds-less work-new parts

So the OBD-II doesn't use a fuel rail mounted regulator? Does anyone have a fuel system diagram they could show me so I could see the differences between the two systems?

I haven't looked it over that well yet, I've just been concentrating on parting out what I don't need at the moment. I have the complete '96 here at my disposal, so getting the pump and all other fuel related parts from it is no problem

Georgia Mike said:

So the OBD-II doesn't use a fuel rail mounted regulator? Does anyone have a fuel system diagram they could show me so I could see the differences between the two systems?

I haven't looked it over that well yet, I've just been concentrating on parting out what I don't need at the moment. I have the complete '96 here at my disposal, so getting the pump and all other fuel related parts from it is no problem

Click to expand...

No- the regulator is in the pump assembly.You have the 96 fuel rail,it has no return outlet.You cap off the return line,swap pumps,fuel rail and injectors,looks to me to be the way to go,Heck, just swap the whole fuel tank,pump already installed.
Wayne

That's what I was thinking, swap the whole fuel system and I'd be good, although I think the '96 pump will fit in my '91 tank, and the '96 has been sitting for a couple of years so it may have a nice coat of rust and gelled fuel in it's tank. I've never done this before so I wanted other's opinions on it. It seems to me like it should work, anyway.