Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: pooljunky on August 31, 2013, 04:26:01 PM

Title: engine swap. 2.5l to 4.0 questions.. and help?
Post by: pooljunky on August 31, 2013, 04:26:01 PM
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

Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: cLAY on August 31, 2013, 06:45:37 PM
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.  :D
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on August 31, 2013, 07:43:16 PM
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..
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on August 31, 2013, 07:45:24 PM
And for the 5.2 I can use the ax 15 I just need to change the belhousing from a Dakota. .
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: BUKI on August 31, 2013, 09:27:59 PM
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 ;)


Sent from my iProne
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: xjpete on September 01, 2013, 08:07:57 AM
 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  :) 
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: hps4evr on September 01, 2013, 01:20:57 PM
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:)
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 01, 2013, 04:19:04 PM
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 :)
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 01, 2013, 04:21:15 PM
I might need the harness if anybody got one laying around
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: BlackYJ on September 04, 2013, 12:13:40 PM
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
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 04, 2013, 11:03:54 PM
Hey balckyj thanks alot.. I thpugh I heard that somewhere.. good to know.. next thing do I need a different fuel pump?
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: BlackYJ on September 05, 2013, 09:25:12 AM
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
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 05, 2013, 10:26:46 AM
Sorry tbi? I currently have a 4 banger..
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: BUKI on September 05, 2013, 04:19:18 PM
Throttle body injection. 1990 and older yjs had it. 1991 and up was mpfi.


Sent from my iProne
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 06, 2013, 12:40:02 AM
Ok kool o have a 2001..  how do I just add the extra injectors on them
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 27, 2013, 07:29:49 PM
So just to make sure the wiring harness for my 2.5l tj will work for a 4 litre cherokee engine?
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: pooljunky on September 30, 2013, 10:49:42 PM
anybody got any idea how I can add 2 injectors to my wiring harness of the 2.5 for the 4.0 litre? 

and anybody would be kind enough to help me weld the new engine mounts that has done it before?

HELP! lol

thanks guys
Title: Re: engine swap. 2.5l to 4.0 or 318?
Post by: JackstandJohnny on October 01, 2013, 09:04:07 AM
And for the 5.2 I can use the ax 15 I just need to change the belhousing from a Dakota. .


when you find one let me know. i've been looking for a 5spd out of a dakota for 2 years now.  they are RARE to find. probably because its a good tranny and good motor combo ;)
Title: Re: engine swap. 2.5l to 4.0 questions.. and help?
Post by: Bnine on October 01, 2013, 09:55:40 AM
http://www.ebay.com/itm/Dodge-Dakota-AX15-to-V8-V6-3-9-5-2-5-9-Bellhousing-94-95-96-97-98-/221240119783?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ADodge%7CEngine+-+Liter_Display%3A5.2L&hash=item3382f051e7&vxp=mtr#ht_92wt_904
Title: Re: engine swap. 2.5l to 4.0 questions.. and help?
Post by: JackstandJohnny on October 01, 2013, 12:35:26 PM
http://www.ebay.com/itm/Dodge-Dakota-AX15-to-V8-V6-3-9-5-2-5-9-Bellhousing-94-95-96-97-98-/221240119783?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ADodge%7CEngine+-+Liter_Display%3A5.2L&hash=item3382f051e7&vxp=mtr#ht_92wt_904

i gave up on ebay a while ago because they won't ship to canada half the time.
same with this on; they won't ship to Canada :( i've been looking (not very hard) on kijiji and waiting for them to be parted out.  mostly i'm lazy haha
Title: Re: engine swap. 2.5l to 4.0 questions.. and help?
Post by: pooljunky on October 01, 2013, 04:48:33 PM
Lol well this is getting a bit off topic lol for the dakota bell housing im pretty sure picknpull would have quite a few of those.

Now abput some welding?
Title: Re: engine swap. 2.5l to 4.0 questions.. and help?
Post by: BlackYJ on October 02, 2013, 12:32:26 PM
Lol well this is getting a bit off topic lol for the dakota bell housing im pretty sure picknpull would have quite a few of those.

Now abput some welding?

You best bet would be to measure a TJ that has a 4L from the factory. 

As for the wiring harness, I know it can be done as that is what was done when I swapped in a 4L to my YJ. However, I had National 4wd do the swap for me
Title: Re: engine swap. 2.5l to 4.0 questions.. and help?
Post by: pooljunky on October 02, 2013, 12:35:35 PM
Welding is now covered.. but lol just need to figure out the injectors and the pin location for number 5 n 6
Title: Re: engine swap. 2.5l to 4.0 questions.. and help?
Post by: pooljunky on October 06, 2013, 10:51:04 PM
Ok guys.. all that has been covered and fixed. New issue...  the transfer case allignment to the rear pinion on the dif.. how is it supposed to be alligned. .like straight? so I would assume that the bolts of the transmission does not allign on the plate for the tranny?


ANy help on that?