I'm getting ready to swap in a '96 4.0L and AX-15 out of an XJ into my '85 CJ-7, and I have a few questions. First off, is the fuel regulator on a '96 mounted on the fuel rail, or in the tank. Secondly, can I use the same aftermarket 20 gal tank that my CJ has? I know I'll need new EFI fuel lines, pump, sending unit, and maybe an in tank regulator, but I'm not sure about the tank itself. I know a 15 gal tank out of a '87-'91 4 cyl YJ will work, but I'd like to know if mine will before I shell out the $ for a new tank. Thanks for the help.

the 96's, should have the pressure regulator in the tank, not on the rail. This is pretty much true for any post-95 4.0L
you can keep your tank, but you will need an external pump (not recomended) or you will need to modify your existing sending unit to hold a stock pump internally.

Sundowner

from what I've learned from this same swap so far is that yes, the regulator is in the tank. you'll need the complete fuel sending unit from a 96 or newer Jeep vehicle. This has the sending unit on the regulator. The problem is that the CJ tank is too shallow to use the new sending unit. an alternate method is to replace the fuel rail with an older one that has a rail mounted regulator and install a return line.

Thanks for the info. Just to make sure that I have my facts straight, the '96 will have the regulator and sending unit in the tank, and will need the newer style fuel pump and sending unit, at a cost of over $500? Or I can swap on a pre '95 fuel rail, and run an inline fuel pump. Do I have all this right? Thanks for any info, this is the one area on this swap that I don't have all the knowledge I wish I did. And working with fuel systems a few :beer: will not solve all problems.

Yes the 96 will have the regulator and pump in the tank. you can swap in a 95 or newer fuel rail with the regulator on the fuel rail and install a return line. however i Think (i THINK) the 95 and earlier rail mounted regulators are not high enough to work with the 96 and newer MPI. Therefore, you'll need a special regulator that you can set to the proper level. these run around 260 dollars from hesco and also other places I've seen. That is why I think it is easier to use a tank and sending unit from a 96 or newer jeep that had the regulator in the tank. that will have the proper pressure. A used tank and sending unit shoul't cost you 500 if you get it from a non jeep wrecking yard(those bastards know what there junk is worth), although I havn't researched this aspect yet. All this i have learned from the writeups that I found on Google.com and also a great deal from the user dorfs on this board. He is an expert on the exact thing that you are doing. If you look through the posts, you will find a few on 4.0 swaps that he had commented on that explains everthing I just said.