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Unread 02-23-2013, 07:50 AM   #1
Sgtrhoads
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1995 YJ Wrangler 
 
Join Date: Jun 2011
Location: Watertown, New York
Posts: 25
2.5L to 4.0L swap

I started this project awhile ago. I have a 95 YJ w/ 2.5L AMC and automatic. Last spring I found a worn out 95 here in NNY with the 4.0L and also automatic. Picked it up pretty cheap. Frame was rusted and cracked, but the engine looked good and ran. I torn it down, had the lip taken out of the cylinders and got the head cleaned. I have ordered a Clegg master rebuild kit that should be in this week. I plan to put it back together and swap it out with my 2.5L. I saved everything I think I needed from that rusted jeep before I junked it. I have the wire harnesses, ECU, XMSN, and a few other things. I am supposed to deploy to AFGN in a very short amount of time.

Does anyone have any pointers or info that might help me get through this with the least amount of issues. This is my first engine rebuild and engine swap. I am an aviation mechanic, and learning my way on vehicles. Any info you guys (and gals) have would be greatly appreciated.

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Unread 02-23-2013, 08:46 AM   #2
schaef89
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1989 YJ Wrangler 
 
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I hope you saved the transmission too. The 6 and 4 cyl have different transmissions
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99 WJ Limited, 4.0L/42RE/NP247
93 YJ, 4.0L HO/32RH/NP231 - Sold
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Unread 02-23-2013, 08:53 AM   #3
Sgtrhoads
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Oh I did. Want sure on that but figure better safe then sorry
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Unread 02-23-2013, 09:05 AM   #4
schaef89
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Ok just making sure since you didn't say that in the original post.

It might be easier to put in 2 more injector wires in your existing harness instead of swapping the hole thing out. The 4 an 6 share the same harness just different injector wire count
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89 YJ S, 2.5L/AX-5/NP231
99 WJ Limited, 4.0L/42RE/NP247
93 YJ, 4.0L HO/32RH/NP231 - Sold
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Unread 02-23-2013, 10:02 AM   #5
Sgtrhoads
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Thanks I'll look at that. Never look at the differences.
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Unread 02-23-2013, 06:56 PM   #6
jeepcrazy93
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1993 YJ Wrangler 
 
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Location: Harrisburg, PA
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When i did mine i added the injector wires. Its tricky but not that hard. Its good that you have a donor vehicle. The miscellaneous parts to do the swap can add up.
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Unread 03-06-2013, 08:18 PM   #7
Sgtrhoads
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Starting to get it back together.
block.jpg   dsc00638.jpg   dsc00561.jpg   dsc00643.jpg   dsc00650.jpg  

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Unread 03-07-2013, 08:22 AM   #8
Que89YJ
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1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
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The harness between the 2 is almost the same. You might have to extend the coolant temp sensor wires and play with the alternator wires. Adding the 2 injector wires is definitely the easiest way to go on the harness. It really looks great! Keep the pics coming.
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Unread 03-08-2013, 08:03 AM   #9
remmons
Some assembly required.
2002 KJ Liberty 
 
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This will be a fun project for you. You will love the end result once you're finished and fire it up for the first time. Keep us posted on your progress.
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Dinosaurland, Utah.
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Unread 03-08-2013, 08:45 AM   #10
bogleparsons
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2013 JK Wrangler 
 
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Location: fayetteville, NC
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Dang I wish i had a 91+ model so i could do the 4.0 swap easier
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If it's not supposed to move and does use duct tape.
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Unread 03-08-2013, 09:15 AM   #11
Que89YJ
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1989 YJ Wrangler 
 
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Hey Bogle. It is easy enough to do ours. It is the same basic swap as the 4.2L guys. I want to do the swap on mine but I just have too many other things to do right now.
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Unread 03-08-2013, 09:53 AM   #12
bogleparsons
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oh, that's good to hear. I thought because of the TBI it wouldn't work.

that motors purty btw, keep us posted.
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Unread 03-09-2013, 02:18 PM   #13
riptide69
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1990 YJ Wrangler 
 
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I was under the impression we couldnt do the swap with a '90 because of the transfercase and the axles being of lower quality than the 4.0 drivetrain..was i given bad information? thats the only reason i havent done the swap.
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Unread 03-09-2013, 05:11 PM   #14
Wild Hare
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Quote:
Originally Posted by riptide69 View Post
I was under the impression we couldnt do the swap with a '90 because of the transfercase and the axles being of lower quality than the 4.0 drivetrain..was i given bad information? thats the only reason i havent done the swap.
axles are the same doesnt matter 2 or 4 banger
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Unread 03-09-2013, 05:13 PM   #15
Wild Hare
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what are the plans for motor mount relocation?
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Tags
4.0l , engine rebuild , engine replacement , engine swap , engine swap wiring

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