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Unread 10-12-2013, 06:53 PM   #1
TrumpyCherokee
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1978 CJ7 
 
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2.5 to 4.0 swap in my 93 yj

I have a 93 yj that has a 2.5 and ax 5 swapping in 4.0 and ax15 from cherokee that ran in the cherokee took the 2.5 yj harness spliced in injector 5 and 6 wiring in the 2.5 harness going to the bulkhead of the pcm for a 95 xj the motor was out of a 91 and the trans was out of the 95 could not get that motor to start and run correctly sounded like it lopes when trying to run. took motor out of another 95 that ran and ran good just to see if it was the motor. took right out of the cherokee and put in yj. this motor starts when it wants to but when it starts it acts like its throwing exhuasst out the throttle body. tried another computer from a 91 and it did the same thing what could be the issu???? i have spark fuel and compression but doesnt want to start any ideas im lost and not sure were else to go. thanks!!!!!!

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Unread 10-12-2013, 07:59 PM   #2
Ohsplat
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The splicing injectors in has me worried. Your 2.5 ran fine, the 4.0 ran fine. You spliced the injectors in and now it dont run fine. Sounds like some type of incompatibility. I know the 93 I have does not have adjustable timing. The 90 does, 95 does not. Im thinking it has something to do with the different years of engine and harness. Maybe its looking for a sensor that it cant find, or something to that fact.
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Unread 10-15-2013, 08:34 AM   #3
Que89YJ
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1989 YJ Wrangler 
 
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TC, check the fault codes and see what the ecu thinks is going on and post back what you find. We can get you figured out:
http://www.jeepforum.com/forum/f12/h...codes-1257145/
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Unread 10-15-2013, 09:01 AM   #4
StanF
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1995 YJ Wrangler 
 
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I'm very interested in your swap - I've got all the parts for a 2.5L to 4.0L swap, and will be doing it sometime next year. Computer issues/problems is the one thing that I'm afraid of - I'm sorry to hear about your problems.

A quick question...How did you clock the transfer case? The XJ AX15 clocks the NP231 much lower than the stock YJ.
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Unread 10-15-2013, 07:38 PM   #5
Nickabis
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1990 YJ Wrangler 
 
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Quote:
Originally Posted by StanF View Post
A quick question...How did you clock the transfer case? The XJ AX15 clocks the NP231 much lower than the stock YJ.
The ax15 is the same between the xj and yj, the mounting holes are drilled in different spots but there is enough area to drill new mounting holes. I drilled new holes in my xj ax15 for my yj by making a cardboard template. Worked great.
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Unread 10-16-2013, 06:03 AM   #6
StanF
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1995 YJ Wrangler 
 
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Quote:
Originally Posted by Nickabis View Post
The ax15 is the same between the xj and yj, the mounting holes are drilled in different spots but there is enough area to drill new mounting holes. I drilled new holes in my xj ax15 for my yj by making a cardboard template. Worked great.
Thanks for the info - when you drilled the holes, did you clock it to the standard YJ position or take the Tcase up parallel?

I want to get mine parallel. I'm not sure if there's enough meat on the rear of the AX15 to take it parallel. If not, I'll use a clock ring.

For anyone else interested, here are some images that explain:

Stock XJ clocking (clocked way down!)


Stock YJ Clocking (about midway between parallel and the XJ)


Parallel Clocking (for a Tummy Tuck)
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Unread 10-16-2013, 07:21 AM   #7
Nickabis
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1990 YJ Wrangler 
 
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I clocked it parallel for a tummy tuck. For some reason I can't load pictures from the app anymore.
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Unread 10-16-2013, 09:56 AM   #8
StanF
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1995 YJ Wrangler 
 
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Quote:
Originally Posted by Nickabis
I clocked it parallel for a tummy tuck. For some reason I can't load pictures from the app anymore.
Cool - good to know it works.

Hope you get your other problem fixed soon.
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Unread 04-21-2014, 12:46 AM   #9
92jeep2540
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1992 YJ Wrangler 
 
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I have a 92 yj and I am swapping in with a 4.0 out of a 95 and I was told to get the wiring harness and ECM it will drop in and Run is that true? just looking for atranny and transfer case right now


any other modifications that I may have to do to it??
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