Need a new fuel pump/sending unit

[Wood90]

Hey I'm new to the forum and I'm finally getting somewhere with my build, but need some help. I have a swb 1990 eliminator 4x4 metric ton with auto tranny and 4.0, all stock. However, my fuel tank is old and my fuel pump is going out and I was curious if I could swap a Dakota 22gal tank and what years would work and what all I'd need to complete the swap. I have tried searching but haven't had any luck finding any write ups that explains it outright (my automotive abilities do not include knowledge of this haha) Thanks for your help!

[buckwheat]

You can do that, but if you're shaky on your skills, think about getting a fuel tank for the 1986 MJ with the 2.1 diesel. I think the spectra number is JP5A. These do not have a baffle inside of them, which allows you to run a cherokee sending unit. The cherokee units can still be had new, just make sure to get the same year as your vehicle. You could also modify the cherokee sender to work in the MJ. 

 

I personally modified the baffleless tank by putting in a custom baffle and the cherokee sending unit. Works very well, and the best part is if it ever goes bad I can just get a new unit and plop it in.

 

If you are set on doing the Dakota fuel tank, I will let someone who knows more jump in. I decided it was too much fab work for me, plus you have to heat and mold part of the plastic tank. It just didn't seem like a good idea. All of that is just my opinion though.

[Wood90]

Thanks for the help! I'd appreciate it if you had him jump in, if it does turn out to be a headache your idea would work great. Currently I just have a 13 gal fuel tank, which is to small for me.

[HOrnbrod]

Thanks for the help! I'd appreciate it if you had him jump in, if it does turn out to be a headache your idea would work great. Currently I just have a 13 gal fuel tank, which is to small for me.

 

No such animal as an MJ 13 gallon fuel tank. The smallest tank in a 1990 MJ would be 16 gallon. But with the baffle setup it doesn't really hold much more than 13 gallons anyhow.

 

You can do that, but if you're shaky on your skills, think about getting a fuel tank for the 1986 MJ with the 2.1 diesel. I think the spectra number is JP5A. These do not have a baffle inside of them, which allows you to run a cherokee sending unit. The cherokee units can still be had new, just make sure to get the same year as your vehicle. You could also modify the cherokee sender to work in the MJ.

 

Good idea, but I don't think you can use the 86 MJ diesel tank because it's designed for a LWB vehicle. It won't physically fit in your SWB rig.

 

EDIT: ^^^ That's wrong. Looked up the tank fitment; it's designed for the 113" wheelbase (SWB), 18 gallon capacity, 29.75" long, so it should fit fine.

 

 

[buckwheat]

Well its a baffleless tank. When I looked it up on a parts store computer it said it was for the diesel MJ. But it is an 18 gallon tank made for the SWB. So cross reference the Spectra JP5A number, because I know that one is correct.

 

Check it out here, and look at the compatibility tab. I know there is not such a thing as an 87 diesel MJ, but that is what their reference is to.

 

OP: I hope someone can give you more information about the Dakota tank. Good luck.

[HOrnbrod]

You're right - I just corrected my post above.  :cheers:

[Wood90]

Yeah I have no idea why it only fills up to 13 gallons haha but it's not in very good shape so I plan just to replace it all. I've located a 22gallon 1997 tank and pump/sending unit for $75, I'll see if I can find if that will work, I appreciate the help!

[gogmorgo]

Have you ever filled it from completely empty? Like, right dry, without the couple gallons still in it when your light comes on...

[Wood90]

Yes I've ran it dry a couple times just to see what mileage and tank size I've got. best mpg I've had is 14 and the tank never fills up to 14 gallons. Also, my gas gauge dosn't work, needle sticks right over the letter F haha