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Comanche 87 to 97

Just saw on comanche club, I spokane craiglsit there is a rolled 91 mj. Could ask him if he's getting rid of the fuel tank... unless your doing the Guage swap also.

On a side note, I remember there being a company making a adapter ring for the mj tank to newer xj fuel pump/sender
 
Copperhead Fab made one, it sucked and leaked. I sold it. Gen Right makes a nice one. There is a guy on CC who is having drive shaft clearance issues with putting the XJ pump in the MJ tank. You have to space the tank down for the FPR to clear the bed. So far the best two options I see are either a Dakota or TJ tank. I've had zero issues in six years with my TJ tank. As far as I know, I'm the only person running one.
 
I’m looking for the cheapest way to feed my 49psi engine, these are the options that I found that not implied changing or puncture the original fuel tank:

1. Stock 97+ XJ fuel pump into the MJ fuel housing, stock float, WJ fuel rail with integrated 49PSI fuel pressure regulator and return line.
2. Stock 97+ XJ fuel pump into the MJ fuel housing, stock float, external aftermarket adjustable fuel pressure regulator near the tank with return line.
3. External aftermarket pump, external aftermarket adjustable fuel pressure regulator, stock float and stock fuel housing.
4. Stock 96 XJ complete fuel assembly unit with integrated in tank 49psi fuel pressure regulator.


I opt for the option #4:
As you may know 95 and older XJ´s and MJ´s use 39psi, 96 only XJ,s use 49psi side mounted fuel assembly with integrated fuel pressure regulator and 97 and later XJ´s use 49psi top mounted fuel assembly with top mounted fuel pressure regulator, so I choose option 4:
Went to my local pick a part and easily found a 96 XJ and pay 22dlls for it

IMG_5631.jpg


Then I cut the connector and match the cables to fit my 97 harness, orange cable is pump positive, black cable is pump negative (chassis), and I pick 2 cables with my multimeter for the gas gauge,

IMG_5630.jpg


The original 96 XJ fuel sending unit will not fit the MJ tank because will impact the small bin inside the fuel tank, so I bend the fuel housing 15 degrees to the right in order to fit inside the MJ fuel tank,



IMG_5637.jpg

*The new location will not be inside the small bin inside the tank and will probably cause problems off-road
And it worked!


Check out the video: https://twitter.com/knkn9/status/697957290486312960
 
The harness is for a 2wd, now with the 4wd transmission and transfer case the speed sensor has to be about a foot farther, so I made an extention,

image.jpeg
 
Now I'm stuck in the taillights and I'm totally lost,

Can someone who has already done this can explain me how to connect the 87 to 97 MJ taillights XJ harness?

IMG_5751.jpg
 
Split the MJ harness to make the top bulbs brake and bottom bulbs turn. Wire them so both top and bottom bulb are dim for parking lights.

Or

Extend the XJ harness and modify the MJ lights to accept the XJ sockets.

Either way works. The choice is yours. I choose the first way.
 
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Split the MJ harness to make the top bulbs brake and bottom bulbs turn. Wire them so both top and bottom bulb are dim for parking lights.


This is what I did.

JIM.
 
I bought new sockets, and made my own rear harness for tail lights. I put "weather pack" connectors on original xj tail light harness, and on my harness. Looks factory.
 
Who is the mfg of this tank? I'm trying to replace mine and am having trouble finding one that has the standoff/fuel pump support shown in this photo.


 
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