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1994 4.0 zj auto into a 1990 4.2yj 5sp

Posted: Mon Nov 27, 2017 2:21 pm
by Dan
I blew my 4.2 up and was given a 1994 zj complete. What will i need to swap drivetrain from zj to yj

Re: 1994 4.0 zj auto into a 1990 4.2yj 5sp

Posted: Mon Nov 27, 2017 3:56 pm
by Stuka
The Zj is going to be an automatic, are you going to use that transmission, or do you want to use the YJ's trans? The answer to this will determine if you need to mod the ECU for not using the stock trans which it controls.

Re: 1994 4.0 zj auto into a 1990 4.2yj 5sp

Posted: Tue Nov 28, 2017 8:19 am
by Shagoneer
Depending on how your crank looks in the 4.2, put that and the 4.2 rods into the 4.0 block and get a little extra torque while you have it apart.

Re: 1994 4.0 zj auto into a 1990 4.2yj 5sp

Posted: Fri Dec 29, 2017 9:34 am
by tgreese
Kind of an odd forum to ask this question <scratchs head>

Maybe the poster thinks this forum covers ZJs?

A Wrangler forum might be able to tell you more about swapping the MPI 4.0 into a YJ. IIRC the ZJ and WJ 4.0L blocks are different, and won't land on the 258 mounts like the XJ 4.0L will. A ZJ forum would know more about that, or maybe the JeepStrokers forum. The have a blocks faq https://www.jeepstrokers.com/forum/view ... ?f=34&t=52 and seem to know quite a lot about swapology.