engine swap. 2.5l to 4.0 questions.. and help?

[pooljunky]

Hey guys.. before I start I wanted to make sure I ask. . What is the easiest converstion and best for the money?

I have an ax 15 with a good tc.. and im thinking the 4.0 would be easiest.. all I really need is the wiring harness from a 4 litre tj and the computer..

Would the wiring harness from 2.5 litre work on the 4l and just add 2 injectors? And plug in into the computer of a 4l?

And except moving the motor mounts is there anything else I should look at ill need to change?

Thanks for your input is appreciated! !

Anything helps

[cLAY]

I don't think a 5.2 would offer much over a 4.0. If going that route go 5.9.

5.2/5.9 use a different tranny than the 2.5/4.0 so now you are into a tranny/t-case swap.

Your best bet is to sell that anemic piddly lil TJ and buy a ZJ, preferably a 5.9. 

[pooljunky]

Lol I had some respect before you said to buy a zj..  lol cant sell the tj.. its great.. and as mentionned I am changing the motor tranny and tc anyways.. but I believe the 4.0 is the way im going..

[pooljunky]

And for the 5.2 I can use the ax 15 I just need to change the belhousing from a Dakota. .

[BUKI]

If you go v8. I'd go 5.0. You lose over 100 lbs and good power. I've always wanted to do it. If you are going to do an engine swap, I'd go v8 for nearly the same amount of money you get that ridiculously awesome  growl


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[xjpete]

 I went from a 4.0 to a Chevy 5.7l , 700r4 and a 231hd tcase . Motor mount kits were available but I didn't like the position it put the motor in so made my own brackets ... to low and forward  . The swap was easy   

[hps4evr]

4.0L swap would be straight forward but you would need harness and computer from donor tj. 5.2 is more work and you'd need an install kit but the gains aren't much over a 4.0L. The ford 5.0 is a nice swap and fits well, distributor at the frint, more power and lighter then 4.0, but you'd need install kit and harness, and they are getting to be 15 years old not at best. Chev 350 would need harness and adapters heavier then 5.0 and distributor at the back, about 15 years old too. Chev LS is a real nice fit, still needs adapter and harness but so many available and new. Comes down to time and money:)

[pooljunky]

Thanks guys.. I think im going with the 4l because im getting evwrything for like 450.. so I think this will be good until I go with another route

[pooljunky]

I might need the harness if anybody got one laying around

[BlackYJ]

You DO NOT need a 4.0L harness as you can wire in the extra 2 cylinders but you DO need a 4.0L computer as you stated in your original post.  This is what I did when I swapped in my 4.0L.  The bulkhead connectors between a YJ and XJ were different so it was easier to wire in the extra cylinders than trying to make the XJ harness work

[pooljunky]

Hey balckyj thanks alot.. I thpugh I heard that somewhere.. good to know.. next thing do I need a different fuel pump?

[BlackYJ]

Hey balckyj thanks alot.. I thpugh I heard that somewhere.. good to know.. next thing do I need a different fuel pump?

The fuel pump is the same as long as you are don't current have a TBI 4 banger

[pooljunky]

Sorry tbi? I currently have a 4 banger..

[BUKI]

Throttle body injection. 1990 and older yjs had it. 1991 and up was mpfi.


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[pooljunky]

Ok kool o have a 2001..  how do I just add the extra injectors on them