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5.2L Magnum XJ engine swap

You're going to wonder what took you so long to do the V8 and how you ever lived without it.

I've wanted about 50 more HP since the first time I towed with this Jeep back when it was new. It just took this long to have an excuse to yank the 4.0L. :)

B
 
your giving me bad ideas.... jeep cherokee 5.9 R/T anyone?
D/C 5.9l has been done. Ray something-or-other had a sharp one at the Fall Fling 10 years ago.
 
Depending on how I like my 5.9L MJ build, I'd toss around the idea of throwing one into a Cherokee. A HUGE portion of the work would already be done for me, like upgrading the interior to the '97+ style so that the electronics will talk to the PCM, motor mount templates, wiring diagrams...oh, and I wouldn't be working with a 20+ year old rusted out Comanche :D
 
I took it out for a spin around the block (4 miles). The trans shifts nicely, The converter locks up as it should, it runs good, and still no MIL. I need to work out an air filter and then work on the hood to cover everything up. Looks like this project is entering the final phase!

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So I fired it up again tonight,.. ..,The motor got up to 180* but didn't go over even though I let it idle for about 10 minutes.
You should check what the normal operating temp for the small block is. Might need to put a higher temp T-stat in it. 'Not sure about the 5.2/5.9, but the 4.0 is still in cold start/warm up mode at 180.

Looking good! :thumbup:
 
I connected the OBDII scanner yesterday. All of the sensors are working and everything looks good. I also figured out why the electric fan runs all of the time. The Dakota with the V8 doesn't run an electric fan! The wire to the ECU is there because it is part of the Cherokee harness. So there must be a pin there in the ECU but it is not programed to run at a certain temp. What I'm going to need to do is run a separate temp controller for the fans which I was planning to do anyway. I just need to figure out where I can add the sensor.

For now I put a 9"X2" carb style air filter on the throttle body. I'm not sure if that'll stay or not. I'd really like a larger filter but unless I do a lot of hood work I don't know what else I can get to work. I'm going to have to think on that.

I only have a few things left and I will be done. Well, as done as you ever really get on a Jeep. I have to make new linkage for the transfer-case, make a tail pipe, and make a hood scoop. In addition I have to put a new A/C compressor in. Some how I lost track of the compressor that came with the Dakota and the pulley alignment of the Cherokee Compressor doesn't match the Dakota pulleys. I also need to get it emission tested. The emission test may prove to be the biggest obstacle yet? We'll see.

I am so totally shocked that everything is working and I basically had to do no trouble shooting of the wiring at all. Maybe this is a testament to how easy the wiring part of this swap is. It really does help that the ECM and Gage cluster communicate properly. The fact that the ECM plug on the harness that stays with the Jeep not only plugs in but is mostly pinned the same is also a big plus.

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You should check what the normal operating temp for the small block is. Might need to put a higher temp T-stat in it. 'Not sure about the 5.2/5.9, but the 4.0 is still in cold start/warm up mode at 180.

Looking good! :thumbup:

Last night with the OBDII plugged in it indicated it was in closed loop, so I assume it's getting warm enough. I'll keep an eye on it though.

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I am so totally shocked that everything is working and I basically had to do no trouble shooting of the wiring at all. Maybe this is a testament to how easy the wiring part of this swap is. It really does help that the ECM and Gage cluster communicate properly. The fact that the ECM plug on the harness that stays with the Jeep not only plugs in but is mostly pinned the same is also a big plus.

B

I have to somewhat agree that the wiring was a lot easier than I had originally anticipated. I'm about 65% of the way through my wiring mess and so far the only two things I have found that don't work in perfect harmony are the horn and the fog lights. I did my setup a little bit differently than you since I ditched the XJ engine bay harness entirely and stuck with the ZJ harness, but after having gone through it once, I probably should have kept the XJ harness.
 
Here is a picture of the air filter I put on there. I'll likely change the filter to a 3" K+N if I keep this set up. Or if I can figure out a way to do a cone style I may go to that but for now this will work.

B

DSC01783.jpg
 
That is a sexy, sexy XJ.
I for one like the old-school air filter, looks good on that rig. I mean, the 5.2 Magnum is basically an MPFI 318, which makes the hot rod appearance bad ass instead of "lame throwback"
And... again... Me Likey.
 
That is a sexy, sexy XJ.
I for one like the old-school air filter, looks good on that rig. I mean, the 5.2 Magnum is basically an MPFI 318, which makes the hot rod appearance bad ass instead of "lame throwback"
And... again... Me Likey.

Well thanks. Actually if I could fit a 14" round 3" thick air filter on there I wouldn't have any problem with an old school setup. This setup may stay anyway though just because it's simple and it gets the job done.

What I think would be a nice looking setup is to get one of the Mopar MPFI intakes, which is like a 2V Victor JR. with injector bungs, and run that with a 14" filter. Unfortunately those intakes are around $500, too rich for my blood. I'm also not sure how that would affect the factory fuel tuning. So I'm not going to run one for now.

B
 
Very nice. In the future maybe. Have you run this intake on the motor yet? Is it lower than the stock 1/4 barrel? Does it run well with stock tune?

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It's official! The Jeep passed the WI emissions test! The guy thought he might have to over ride the system because the motor and computer were different than what came with the Jeep. It turned out that he didn't have to do anything special. He plugged it in and hit test (they just plug into the OBD port here). Even with the system set up for a '98 Cherokee it tested and past it. Very cool. It now has its tags.

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D/C 5.9l has been done. Ray something-or-other had a sharp one at the Fall Fling 10 years ago.



The vehicle is owned by Ray Pili and started life as a '85 2.5L NP 207 D30/D35 (IIRC). The Jeep was painted Orange and a 5.2L from a Dodge Dakota was installed with the automatic transmission, D60/D44 3.73s, Klune V splitter and Atlas 3.8.
 
Here is a picture of the air filter I put on there. I'll likely change the filter to a 3" K+N if I keep this set up. Or if I can figure out a way to do a cone style I may go to that but for now this will work.

B

DSC01783.jpg

wow that looks great :thumbup:
 
Could you get us a pic from the side with the hood closed? 'Curious how far everything sticks up.

That air cleaner probably flows more air then any cold air setup made for the 4.0.
 
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