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MJ Fuel Pump

jeeping4fun

NAXJA Forum User
Location
Corona, CA
I just purchased a new to me 87 manche short bed that was originally a 4 cylinder. It was swapped over to a 4.0ho out of a 93 xj donor. The fuel guage is reading backwards and after some researched learned all about the ohm readings changing and how they flipped polarity around 1990. I read mention of flipping the wires behind the guage or at the pump itself. Not sure what is best.

Also how or what did they do to make the pump work for the 4.0? You can't buy an MJ pump from what I read and swapping in an xj pump I also read doesn't work.

I don't care if the guage doesn't read that accurate I just want to be sure I habe a 4.0ho pump and the guage moves in the correct direction. I'm going to pull it out this weekend but I'm not sure what to look for.

I read somewhere AutoZone sells a pump assembly that works in a MJ tank without the pan in it. What years/style have pans in the tank?

Thank you in advance for your help
 
I don't have a solution but I have a location that you might be able to find your anwser faster.

Please remove if against the rules but do some research on comancheclub.com and ask the guys over there. They will have much more experience and more MJ specific info on that forum.
 
why not run the orignal pump? if it doesn't have the pressure maybe an inline pump. years ago when I was trying to swap my 96 xj stuff over I ran into that issue, I planned on going with copper creek fab or something, basically an adapter ring to run the xj pump assembly in the mj tank.

Sent from my SM-G900V using Tapatalk
 
I don't have a solution but I have a location that you might be able to find your anwser faster.

Please remove if against the rules but do some research on comancheclub.com and ask the guys over there. They will have much more experience and more MJ specific info on that forum.

I'll give it a shot. Seems like it should be common knowledge since so many people swap HO motors into pre 91 mj's. Thanks for the site

why not run the orignal pump? if it doesn't have the pressure maybe an inline pump. years ago when I was trying to swap my 96 xj stuff over I ran into that issue, I planned on going with copper creek fab or something, basically an adapter ring to run the xj pump assembly in the mj tank.

Sent from my SM-G900V using Tapatalk

I'm not sure it is the original pump. I'll look into the adapter ring. Thanks
 
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