5.2L Magnum XJ engine swap

[Bloose]

so im about to undertake this swap with a 5.2 out of a 2000 ram 1500 into a 2.5 87 comanche, wiring is racking my brain right now, any idea what i will have to do to make it run happily and have everything work?

Don't really know what advise to give you. Wiring is always a PITA with a motor swap on computer controlled vehicles.



One advantage of the 318 swap into a late model XJ compared to say an LS swap is that the wiring is similar. Many of the plugs and connectors are the same though not all and of course there are lots missing. But the computer connectors are the same, injectors, etc.



For you, you're swapping a late model motor into a Remix era XJ which to me means all of the wiring from the current motor should be yanked. All of the wiring from the Ram should be swapped in. That may cause some issues if the computer cannot be located roughly the same as it was in the Ram. You may have to shorten some wires and lengthen others.



Butt splices are a major no no so you have a few choices there. Either get really good at soldering or buy high end waterproof connectors and the associated tools to crimp the wires and use them to do your splicing.



Any way you go about it the wiring is going to be a bog challenge but obviously not your only. You have to fan motor and trans mounts, all of your exhaust, fuel lines, etc, etc.



Sorry I cannot be more help,

B

 

[eflores]

do you intend to keep the stock dash?

 

[kpeeks]

Awesome swap.

 

[shelbyluvv]

You are in for a real treat! You have a OBD-II engine and a RENIX XJ. You have a couple options. None of which are going to be easy or fun.

You can convert the Jeep to OBD-II dash and wiring.
You can retain the old style dash and use a 96 dash harness and column.
You can convert the engine to OBD-I by swapping out the sensors.

Either way you are in for a ton of wiring unless you pony up the cash for a $900 harness.

On my MJ I went with a OBD-I ZJ engine and harness. I had to swap out my dash harness for a 94 XJ harness. Finally I had to find the HO era MJ fuel pump sender so my gas gauge would read correctly.

 

[Kittrell]

Finally I had to find the HO era MJ fuel pump sender so my gas gauge would read correctly.

That is where the real fun begins!

 

[eflores]

i have one that needs the pickup re braised

 

[kastein]

You are in for a real treat! You have a OBD-II engine and a RENIX XJ. You have a couple options. None of which are going to be easy or fun.

You can convert the Jeep to OBD-II dash and wiring.
You can retain the old style dash and use a 96 dash harness and column.
You can convert the engine to OBD-I by swapping out the sensors.

Either way you are in for a ton of wiring unless you pony up the cash for a $900 harness.

On my MJ I went with a OBD-I ZJ engine and harness. I had to swap out my dash harness for a 94 XJ harness. Finally I had to find the HO era MJ fuel pump sender so my gas gauge would read correctly.

Or you can buy two FSMs on ebay, one for the donor and one for the recipient, and spend a day or two puzzling through what splices to what. I've done a couple EFI 4.0 swaps (yeah, 4.0 vs 5.2, whatever, it's not THAT big a difference when you're splicing up a harness) into carbed YJs and old CJs now with factory gauges and kept everything working. The second one was cake, fired right up on the first try.

Best done this way if you know wiring pretty well though.

One of these days I should put together a guide on it. Hardest part is getting a factory tach working, but the lucky thing is that RENIX tachs are different 4 vs 6 cylinder (a resistor is different inside, per one of the RENIX guys, which calibrates the pulse rate it's expecting) so swap that resistor out for the right value and your V8 ignition coil primary negative will drive your modified RENIX tach no problem.

 

[Wolfe311]

So easiest way would be to go ahead and swap interior harness dash and column out of a 96?
I have the full harness for the 5.2 completely intact still on the motor along with the factory computer
Not too worried about the fabrication, that's easy, the wiring is my nemesis

 

[kastein]

Remember you will also need the steering intermediate shaft when you swap the column. 94 down are all the same IIRC (there may be a split 86- vs 87+, I know very little about 84-86 as they all rusted out a decade ago up here) but 95/96 are different from them, and then 97-01 are different from those.

 

[bamajosh]

Are the computers from the Dakotas able to be tuned like the computer from Mustang was able to be tuned?

 

[Johnnie Walker]

Are the computers from the Dakotas able to be tuned like the computer from Mustang was able to be tuned?

Dakota/Durango ECU are tunable. When I had my Dakota years ago, I used to frequent the dakota-durango.com forum. There was at least a few people that tuned them. I would go over there and check that part out.

 

[kastein]

96-up Dakotas use basically the same JTEC hardware as XJs, IIRC. Anyone who can tune one of those (there are a few groups out there now) can tune that stuff too, most likely.

Can you do it with free/cheap enthusiast software? Not yet, AFAIK.

 

[bamajosh]

Thanks guys.

 

[rockosocko]

Wanted to bring up this thread for an update on if there was any issues and whatnot..

Found Backwoodsoffroad.com and talked to Evan who said that some peeps are using the YJ, CJ Magnum frame mounts to use in a XJ.
ALSO, he can make a stand alone magnum harness from a donor harness.

Please post more.

E

 

[shelbyluvv]

$1400 for a harness last I checked

 

[5.9longarmXJ]

Just did this, used advance adapters universal motor mounts. Modified them and used my OEM mounts that bolt to the unibody frame. Basically cut off the pedestal for the 4.0 mounts and welded the advance adapter mounts to that them. Then built adjustable mounts on the motor side that allows for back and forth adjustment. made it easier when placing the motor. Did the wiring myself using two FSMs. The wiring is much easier than you think. Time consuming, but pretty easy to figure out what goes to what. I posted all the wiring info on my build thread.

 

[shelbyluvv]

I used V8 ZJ mounts. Damn near bolted into the stock location. I also made my own harness. Very easy to do.

 

[John D]

$1400 for a harness last I checked

People pay that? Holy crap...

 

[Demonoid369]

People pay that? Holy crap...

With people like me who are absolutely terrible at electronics.., ya I can see people paying it lol

 

[rockosocko]

I used V8 ZJ mounts. Damn near bolted into the stock location. I also made my own harness. Very easy to do.

Thank you for adding.
I built the motor (95 Grand Cherokee 5.2 magnum and a NV3550 from a '97 Ram 1500) about 3yrs ago for a little mighty max 1ton long bed but found out that the starter and steering box wanted to be in the same spot:tears:

I just bolted on some older Dodge truck STOCK motor mounts that's basically some channel cut on an angle to bolt to the "ears" on the block.
I made it a center sump,(for the cross member) but for this one Ineed to go back to the rear sump and want it down as low as I can.

Mine will be carb'd since I already have the 250.00+$ intake on there and if I want later down the road go FI I'll do the stand alone harness and OBD-I cluster, so I won't have to go through the PCM to use my gauges.

Thanks E

Shelby, may I PM you for pics of how yours sits in the bay?