Hey all, I have been a longtime lurker, but have not posted much previously. I am having a bit of a fuel system issue, hoping someone here can help.

Here is my issue. I have a 1992 Jeep Cherokee (XJ) Laredo. It is currently undergoing multiple upgrades. I will be posting a thread about my build once it is more complete. I was removing the gas tank to repair some rusty floorboards when I noticed a small leak in the tank, as well as some rust around the tank. While this sucks, it is not too terrible as I am wanting to upgrade to a larger tank anyway.

I have decided on the GenRight Fuel Tank (https://www.4wheelparts.com/Performa...=G%2fRGST-3003). It is 30.5 gallons, 10.5 gallons over stock! Additionally, it fits in the stock fuel tank location without modification, and has a built in skid plate. I know there are cheaper options suck as the Sunset Metal Fab AMC-2 which is 32 gallons and about $400 cheaper. However, it hangs too low and cannot accommodate a skid plate.

 

Here is my issue. The new tank requires the newer (1997+) fuel-sending unit. As I understand it, the 1992 Jeep Cherokee sending unit and fuel gauge are 0 ohms empty, 90 ohms full. The new (1997+) fuel-sending units are 240 ohms empty, 33 ohms full. Please correct me if I am wrong with these numbers. I need to find a way to make the fuel tank compatible with my fuel gauge. I have searched and not come up with a great answer so far. Here are the options as I see them.

1. I have discovered that the new fuel-sending unit can be wired directly to the old wires and the pump will work. However, due to the difference in ohms, the stock fuel gauge will not work. Most guys who have done it this way have just used their odometer to estimate how much fuel is left. While doable, this is not really an option for me as I like to have an accurate fuel gauge.

 

2. I can buy an aftermarket fuel gauge that is designed for the 240/33 ohms system. AutoMeter makes plenty of gauges that would work. I currently have the AutoMeter dual A-Pillar pod. The top pod has this transmission temperature gauge mounted:

AutoMeter also make a matching fuel gauge:

Unfortunately, they only have it in the 0/90 and 73/10 ohm ranges. They do not make a Jeep 240/33 ohm gauge. There are 240/33 ohm gauges that come close, but none that match perfectly. By going this route I would have non-matching gauges, a stock gauge that I cannot remove as the instrument panel is one large piece so it would just sit there non-functional, plus I would use up my other A-Pillar pod which I was planning on using to mount a transfer case temp gauge. So, option 2 is better than option 1, but still not ideal.

 

3. That leaves option 3, which is the point of this whole post. There has to be some way to adapt or convert the new tank and fuel-sending unit with the old fuel gauge. I have thought of a couple of possibilities and am looking to you guys to help me brainstorm and offer advice or suggestions.

Possibility 1: Here is the 1992 fuel sending unit:

Here is the new fuel sending unit:

For those of you with experience, can I straighten out and adapt the older style sending unit and make it fit into the same hole as the newer sending unit? This seems like it would be the simplest solution, but I do not know if the tank holes for the sending unit are the same size and style for the two different units. Any info or insights would be helpful.

Possibility 2: If the older style sending unit will not fit into the newer sending unit hole, is there a way to remove the 240/33 ohm sensor portion (not sure if that is what its called), and replace it with a 0/90 ohm sensor unit. I know AutoMeter and others make aftermarket units, and I could always steal the one off my current stock tank if its possible.

Possibility 3: Is there a device that can take the 240/33 ohm signal and convert it to a 0/90 ohm signal?

Possibility 4: Any other solution you all may have that I have not though of.

Thanks in advance for the help. I know my post is long, but I figure the more detail I can provide, the better responses I will get.

 

Someone has to have some info regarding the fuel systems. I figured people would be happy to not have another thread discussing which lift / which tire size. Can anybody point me in the right direction at least? I have done many searches and not found what I am looking for.

 

Cut the mounting hole out of the old tank, weld it into the new tank. The sending units are completely different in shape and orientation, so the fuel gauge may not be accurate, but it will work.

 

No experience, so take this for what it is worth.

It looks like the sending unit from the old one is attached to the side of the pump. I say attach it to the side of the new pump. Might have to fab up a basic bracket that can be attached to the sending unit and hose clamped to the new pump. Might have to do the attachment inside the tank to get it to fit through the hole.

Or find an electronics guy that can rework the older gauge to operate off of the 240/33 signal.

Or find an electronics guy that can make a circuit card/PLC that translates the signal from 240/33 to 0/90.

I'm no electronics guy, ignorant to that stuff, but the signal converter may be the most elegant solution. I'm sure it can be made up, we've sent a man to the moon after all.

EDIT - I found this thing: http://www.classicparts.com/1947-87-.../#.WZWuFq2ZNE4

$135 should do what you want. BAM!

 

Thanks for the ideas. Unfortunately the welding idea won't work as the old tank is steel and the new tank is aluminum. Way too many hurtles to overcome combining 2 different metal types. I did more research on the sensor that was posted (pictured below). Seems like the best answer and probably what I will do. Much less fab work, much less money, and I still have use of my factory gauge. Plus, it can be calibrated to ensure accuracy.

 

personaly id just to the vent mod, its good for 6-7 gallons and only costs like 10$

 

You may notice if you read the original post, that his tank is leaking. Not sure how a vent mod to increase his leaking tank's capacity would be a benefit here.

 

well it'd defiantly go farther

 

Might try looking at a ZJ tank. Supposed to fit and more capacity. They have top mounted fuel pump hole.

I have 2 ZJ tanks waiting for install into my '98s.

 

Did you end up using this solution? If so how is it holding up? I’m thinking of going the same route on my -92 xj.