Gas tank is empty at 1/4? only 9 gallons??

njchuck · 01-29-2009, 11:13 PM

Hello everyone I got a gas tank that is being a pain it seems to only hold 9 ish gallons of gas and right before it hits 1/4 tank it runs out of gas!!

Anyone got any ideas i was thinking of dropping the tank and removing that pipe in it .... this makes the tank hold what amount??
Last question do i have change the fuel pump if i make this mod?
Thanks everyone

larrylarch · 01-29-2009, 11:54 PM

you do not have to replace the fuel pump to do this mod. I gained about 4 gallons when I did it to mine. I run out of gas when my gas gauge reads a little over 1/4 tank which is just a quirk about the wrangler gas gauge after a while. It is expensive to replace the sending unit if you can find one. I drive my jeep by mileage on the odometer instead of the gauge. 9 gallons seems to be a few gallons short of what I would usually end up pumping into mine when it was empty before I did the mod to my tank. If you do drop your tank, just push the inner tube into the tank and then pull it out through the access hole where you fuel pump mounts. I found that easier to do then to try and pull the tube out the other way

**timatoe** · 01-30-2009, 11:24 AM

Well let's see here,,,, 15 gallons/4 = 3.75 gallons. So, 3/4 tank = 11.25 gallons, you're just about right I'd guess, considering that YJ gauges are rarely dead nuts accurate. Try this...... http://www.jedi.com/obiwan/jeep/15to20gal.html, that's what Larry was refering to.

**rustywrangler** · 01-30-2009, 11:27 AM

Quote:

Originally Posted by njchuck

Hello everyone I got a gas tank that is being a pain it seems to only hold 9 ish gallons of gas and right before it hits 1/4 tank it runs out of gas!!

Anyone got any ideas i was thinking of dropping the tank and removing that pipe in it .... this makes the tank hold what amount??
Last question do i have change the fuel pump if i make this mod?
Thanks everyone

I think your problem is more severe than just an off gauge. If you are "running out of gas" and can only fit 9 gallons in, then you have something internally wrong with the vent hose, mod listed above, OR the fuel pump pick up is not where it should be. I would do that mod, but if it continues, it sounds like you need to inspect the fuel pump assembly.

**timatoe** · 01-30-2009, 11:36 AM

Quote:

Originally Posted by rustywrangler

I think your problem is more severe than just an off gauge. If you are "running out of gas" and can only fit 9 gallons in, then you have something internally wrong with the vent hose, mod listed above, OR the fuel pump pick up is not where it should be. I would do that mod, but if it continues, it sounds like you need to inspect the fuel pump assembly.

Crap, somehow missed the running out part.

Slickbr · 01-30-2009, 12:36 PM

Have been doing alot of "Muddin'", I lived in FL with my 1st YJ and did alot of in the mud 4 wheeling'..... mud and dirt will get packed into the space between the tank and the skid plate. This in combination with a defect in the tank (if it's poly) will force the bottom of the tank to heave up and lift the Gas gauge float to stop prematurely @ the 1/4 full level. It happened to my 93 YJ. The Jeep dealership in Palm Harbor, FL took care of the problem by dropping the tank and replacing the defective tank under warranty.

Brando

njchuck · 01-30-2009, 11:58 PM

Thanks for the info guys looks like i just need some warm weather and just drop the tank to get a look at what is what. It is a pain in the backside because I have to go to the gas station to top it off every day because of my 110 or so mile drive drive to and from work. Oh well I need to do some welding to the frame back there anyhow......sucks to be lazy!

**asbury** · 01-31-2009, 07:03 AM

i didthe fuel tank mod, you do not need to change the pump, first check and see if your jeep has a poly tank or a metal tank, if it is poly do the mod,i can put 20 gal in my tank after i did this mod

**rustywrangler** · 01-31-2009, 08:17 AM

Quote:

Originally Posted by asbury

i didthe fuel tank mod, you do not need to change the pump, first check and see if your jeep has a poly tank or a metal tank, if it is poly do the mod,i can put 20 gal in my tank after i did this mod

I am not trying to jump down your throat here at all, but reread his post. Even if he does that mod, he is still having a significant problem with the tank.

**asbury** · 01-31-2009, 09:19 AM

did the 92's have poly tank or metal????,,,,,,,,,
his problem could be that there is an obstruction in the vent not allowing him to fill his tank to it's capacity, this is a free mod which i would try first before dropping the tank, i know he said he needs to do some welding back there any way and he wants to wait till it warms up to do that ,it only takes about 1 hr to do the tank vent mod

**stu1021** · 01-31-2009, 10:09 AM

Mine '90 was having a similar problem when I bought it. When I dropped the tank during the engine swap, I discovered that the plastic sleeve on the mesh pick up/filter assy. had cracked and allowed this piece to fall off the bottom of the fuel pump assy. so the pick up no longer reached to the bottom of the tank. I would start to run out around a 1/4 tank indicated - especially if I went around a hard corner. This I theorize was because, with the shortened pick up, the baffle tray in the bottom of the tank was no longer deep enough to keep gas going to the fuel pump. The bad thing about this is that it would also allow any junk that makes it's way into the tank to be sucked up into the fuel pump. I have the 12 gallon metal tank but I would imagine others would behave the same way.

azgurney · 01-31-2009, 10:18 AM

When you do drop the tank make sure the gauge reads empty when the float is at the bottom of the tank. Also move the float slightly and make sure it is changing correctly on the guage. If it does not read empty when the tank is empty bend the float arm till it does. My guage reads fairly accurate since doing this.

**asbury** · 01-31-2009, 10:33 AM

what year did jeep change from metal tanks to the poly tanks,, i don't have my repair manual in the house ,
what stu1021 says makes sense if yours has metal tank

**Mr.B** · 01-31-2009, 11:26 PM

Quote:

Originally Posted by asbury

what year did jeep change from metal tanks to the poly tanks,, i don't have my repair manual in the house ,
what stu1021 says makes sense if yours has metal tank

You have a poly tank.

To the OP. Mine did the same thing at a 1\4 tank, after I put a dent in the skid plate. The mod will only get you farther down the road. The problem will still be there. I bought a Warn skid plate, and the problem was solved

**Mean Max** · 02-01-2009, 12:25 AM

I agree with Rusty, if he's "running" out of gas, and can only put 9 gallons in after that, there is something else at play here.

As far as the gauge reading 1/4 tank when it runs out, I would suspect that possibly the float arm may be hanging up on the baffle inside the tank, there's not much clearance between the baffle & the path of the float arm.

Just a thought.