I think this is a bit more advanced than newb but I need an answer before tommorw anyway.

I am trading for this thing and I want to know that I'll be able to get it running with the parts I have.

Specs are
87 yj that had a 4.2 in it.
Drive train is a 94yj engine 4.0/ax15/231 w/ a sye (all from the same vehicle)
He has a 2000 fuel injection setup with the bored out throttle body and wiring harness from the 2000 tj it was connected to. He also has a tarus fan to cool it.

Can this work?

have fun...... All the plugs will be different, forget about the computer, and using the coilover plugs i belive are on it. It would be alot easyer to get a 91-95 yj 4.0 harness and computer (obd 1) from a bone yard and the interior harness too.... expect alot of referencing of schematics and splicing late at night, but you will get it!:D
I just finished a 2.5 to 4.0 swap but i was lucky to have harnesses and like years to swap from, goin carb to MPFI will be fun! You will also have alot of little stuff to do, like put in an 02 sensor, install a 91 yj VSS if you are goin to retain your stock spedo.. stupid stuff like that.

I'm pretty sure he has the entire intake, fuel rails and all from the tj. I realize everything from the yj will be different though.

If he uses the rail he has he will need to get a different fuel sending unit (tj, or 96+ xj) to adapt for his tank. The rail that he has is a returnless system, and he will need to plumb in a vacum line from the front to the back to control the in tank FPR. Maby he can take the pump and fpr and adapt it to his current sender, so that his gas gauge still reads true... At any rate since hes goin carb to FI he will need to change his pump back there.

Im not saying its impossible, but to get that 2000 harness to work right for you would seriously cost you alot more time, money, and agrivation then just lookin around at the bone yard, or for a part out on your local forum and get a 91-95 harness and computer. Pretty much to get the obd2 set up working right you will need 2 o2 sensors, a good cat, an evap system that matches that of a tj.. the list goes on. You will most likley have a check engine light on all the time, and it may run like a bag of ass unless its set up perfect. Do you have the 2000 computer? Maby sell that harness to reclaim some money for your new one? I got a 95 yj harness from the firewall out with computer for 40 bucks. It will save you alot of time and money to go that route.

So, All I should need is the harness and cpu out of the 91-95 yj and that will make the project easier. Cool.

One other question, I think he has the throttle body off of the 2000 on there, do you for see any issues there?
He also might have the entire injection system off of the 2000, should I pull that off of the 91-95 yj as well?

Thanks CJ

As far as the throttle body, that can get re-used. The map sensor will be on the side of it, but im my opinion that is a better spot then on the fire wall... it looks alot cleaner. The plugs will all be different but just snip off the plugs from the 2000 and solder them on to your 91-95 harness. Then extend the map plug to your t body and you will be good. Since you have the metal tank and only the low psi line goin to your engine, you will either need to get a yj fuel tank and sender, or if your build is lookin at a fuel cell get one with a tj sender. The yj sender will be a 2 line job, one high psi to your fuel rail, and a return from your fpr on the rail to the tank. If you get a tj sender in a fuel cell you will be able to retain your 2000 returnless fuel rail, and just run a hi psi line to it from the sender and a vacume from the intake manni to the tank to control the in tank fpr. Its really up to you, depending on what you want to do, but if you go the yj tank route and are keepin it under ur rig, its a nice upgrade from steel to polly:D

Thanks for your help, you may be getting pm's from me in the future.

glad to help, its really not difficult with a basic understanding of fuel injection and a good schematic book.