Add 5 gallons to your YJ's gas tank in less then 1/2 hour??

[sebastian22]

all YJs from 91-95 have a 20 gallon tank. the factory decided to make them all 20 gallon tanks, but they put a hose inside to trick the tank into thinking it was full at 15 gallons. as a result they were able to charge more money for the "upgraded" 20 gallon tank, but save the time and money of having to actually make 2 different tanks.

[jeepercreeper77]

so the 90 has a 20gal tank or no? if not does someone make a replacement tank that fits in the stock spot that would be 20gal.

[Jeeples]

There were two tanks made for Pre-'91 YJ's:

A 14 Gallon steel tank and a 19 gallon plastic tank (however it may also be steel, but I recall the 19 gallon tanks being plastic).

[Alacran]

Just did this adjustment on my 94. You'll notice that unless you change the fuel tank sender the fuel gauge reads full for alot longer. I've got 106 miles on my new tank and it still reads full.

[romanella]

How difficult is it to do this? The instructions posted are good, but I'm sure I'll get hung up somewhere... Not really sure what I'm looking at.

[jeepnphreak]

Originally Posted by Alacran

You'll notice that unless you change the fuel tank sender the fuel gauge reads full for alot longer.

How do you go about changing the fuel tank sender?

[jeepnphreak]

Originally Posted by jeepnphreak

How do you go about changing the fuel tank sender?

Never mind I found out how. About $200 at the auto store.

[rugbynut]

Originally Posted by Alacran

Just did this adjustment on my 94. You'll notice that unless you change the fuel tank sender the fuel gauge reads full for alot longer. I've got 106 miles on my new tank and it still reads full.

So have you ever gotten your build sheet from Jeep. If so, did it say that you had the 20 gallon tank or not?

My build sheet says that I do, but in 11+ years of owning it I have never been able to get it to take more than 14-14 1/2 gallons at any one fill up. Admittedly, I have never run it completely out of gas, but right after I got my build sheet I was extremely curious and ran my gauge down as far as it has ever been. When I finally filled it, it only took 14.74 gallons topped off completely.

My question is, does the build sheet on those years always say 20 gallon tank, since technically it is?

[rustywrangler]

Originally Posted by Jeeples

There were two tanks made for Pre-'91 YJ's:

A 14 Gallon steel tank and a 19 gallon plastic tank (however it may also be steel, but I recall the 19 gallon tanks being plastic).

15.5 Gallon steel, 20.1 Gallon plastic or steel depending on what model.

[sebastian22]

Originally Posted by romanella

How difficult is it to do this? The instructions posted are good, but I'm sure I'll get hung up somewhere... Not really sure what I'm looking at.

its not very difficult at all. follow the directions posted on the links above. i believe one is 4x4wire... and the other is jedi. theyre very detailed but heres the basics (at least what i did).

1. locate the gas tank fill vent hose. (on driver side, rear most hose connected to the tank.

2. if you got small hands and the right tools you can skip removing the gas tank and go on to loosen the hose clamp and disconnect the hose where it connects to the gas tank.

3. once you remove the hose you will see a neck on the tank where the hose connected, and inside you will see another hose.

4. use a flat screwdriver and some pliers to completely remove that hose. (this will take some work as the hose is really tight)

5. either cut the hose to 3" and re-insert it, or just toss the whole thing in the trash.

6. reconnect the fill vent hose and tighten the hose clamp.

7. go to the gas station and fill up your tank.

the only reason to lower your tank is to gain better access to the hose clamp. im too lazy to do that so i used a socket with a long extension, a swivel adapter, and a socket that fits on the hose clamp. either way you decide to do it, good luck and have fun.

(edit: i can post some pictures later when i get home)

[93YJfalcon]

Originally Posted by 70sElvis

My suggestion is for everyone to check how much they currently hold before doing this mode. I was new to the jeep community and found this mode. I tore into the mode only to find out that one of the POs had already made it. Just a suggestion.

Me too.

[DownNDirty]

I did not lower the tank I just used tin snips to cut the old clamp off as I did not have a socket to reach it.
For me the worst part was pulling out the inner hose.
I am at 80 miles and still shows full.Yeah

[jeepsurf]

I asked JeepEngineers this:

Quote:
Originally Posted by jeepsurf:
Have you guys heard about the modification to the 2nd gen 92-95 YJ's 15 gal gas tank where by cutting the vent tube are able to acheive 20 gal capacity?I have a 1990 yj and I think its an actual 15 gal tank, so I cant preform this mod. If this is so, will a 92 - 95 factory tank fit in my 1990?


JeepEngineers: YJ ?/ that was TJ I think. Never heard of this for a YJ ??

01/29 Q/A Session - Jeep Wrangler and Wrangler Unlimited

Whats the deal? Can I get a 15g (aka 20g) stock 2ng gen tank and put it on my 1990?

[mdo817]

My '90 model had a 20 Gallon/Plastic, it's identical to the plastic tank in my '92. I took it out and swapped it into my '92 because I knew it was clean. The sending unit seal is the same all the way back into the CJ's as far as size and bolt pattern.

[Jeepinjon]

Originally Posted by swedishdwarf

I don't know about the build sheet, but YJ gas gauges are notoriously inaccurate.

Yup, my gauge will read 'Full' while I'm making the hike to the gas station toting the jerry can. My Jeep's got a hell of a sense of humor like that.