Mutliport Fuel Injection Junkyard Swap

[Rescue Diver]

I know there are numerous ways and kits available to retrofit Fuel Injection on an old CJ, but I'd like to keep this thread exclusively about doing a Junkyard swap of the OBDI Multiport Fuel Injection from a 1992 to 1995 Cherokee or YJ, what parts are required, and how it's wired in.

At least for now, I still plan to stay with the carburetor when I install my new 4.7L stroker, but curiosity got the better of me.

Thanks to the 4.0 engine I purchase for my Stroker Project, I now have a 1995 4.0 intake, throttle body, injectors and throttle position sensor. I've been trying to find out specifically what parts I'd need to complete a junkyard swap. I'd need a crank position sensor and fly wheel, and I'm assuming I'd also need an oxygen sensor with a bung welded in my down pipe. Does the 1995 MPI have one oxygen sensor or two? What kind of electric fuel pump works best for this, a stock(In tank) pump, or an good external. If stock, will a stock pump assembly even work in a CJ tank??? If external, what pressure and gallons per hour are required? What about the fuel pump cut off. Will the computer still cause the pump to shut off after a few seconds to pressurize the lines when you first turn on the key if you don't start the engine? What about ignition. Is it mandatory to have the ignition timing computer controlled using a stock distributor from the donor vehicle, or can you run a manual adjust distributor and set the timing yourself?

 

[Sasquach]

The 95 system is what the Mopar system is based on and mine has one O2 sensor. The fuel pressure is based on what you do with your engine and what injectors etc. I'm thinking an external pump that makes approx 70 psi followed by an adjustable regulator.
Here's some good injector info.
Tech Specs

 

[Rescue Diver]

The 95 system is what the Mopar system is based on and mine has one O2 sensor. The fuel pressure is based on what you do with your engine and what injectors etc. I'm thinking an external pump that makes approx 70 psi followed by an adjustable regulator.
Here's some good injector info.
Tech Specs

Thanks! I knew you used the Mopar kit which is a nicely packaged version of what I'm investigating. 70 PSI is probably a good rule of thumb. I know my ex girlfriend's 2001 Cherokee had ove 90 psi on the guage, and I seem to remember reading somewhere that MPI will function on as low as 35 psi, but I figure that would starve some engines at higher RPM's.

Jeepstrokers.com threads tell of several different makes and models of cars to steal the right size injectors for a stroker from.

Since my new 4.0 block requires that I switch to an electric fuel pump anyway, I'll probably go ahead and get a pump and regulator to feed my carb that'll also work for the injection with the regulator turned up, in case I ever decide to switch to the dark side.

 

[doublec]

I did the head swap from a 91 XJ on my 77 CJ7 . Kept the intake manifold, harness and ECU. If you go this route PM me I can help with the wiring.

 

[Rescue Diver]

I did the head swap from a 91 XJ on my 77 CJ7 . Kept the intake manifold, harness and ECU. If you go this route PM me I can help with the wiring.

I'm already running a 1995 XJ head with a carb. Now I have the intake and FI hardware that goes with it just laying around because of a 4.0 purchase for the block. As I stated earlier, I'm not planning to make the switch to F.I. with my 4.7L stroker build right now, but I'd be very interested in the wiring info so if I decide to do it later I'll already have it.

It would also be good to have it all here in an easy to search thread in case others want to build a budget F.I. system for a few hundred at most instead of buying it all packaged from Mopar for over two grand.

 

[Rescue Diver]

I picked up a complete wiring harnass from a 1993 cherokee with crank position sensor, distributor, temp sensor, MAP, temp sensor etc....

Does anyone know a good link to show what un needed wires to remove and the wire colors and location for the five wires to fire? Hopefully with pics!

I'm wanting to keep my existing headlight, washer pump, horn, heater blower and alternator wiring if I do the swap. I just want the bare bones FI, sensor and Ignition wires to be left.