Fuel Tank Question - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 02-20-2013, 09:53 PM   #1
Newb
 
Join Date: Aug 2006
Posts: 10
Fuel Tank Question

Hello Everyone.

Sparing the details of why, I replaced the fuel tank in my 2000 TJ with a used model. Once done, I found that I could'nt fill it past the 1/2-full mark. The pump simply won't allow it, and the fuel will run out the filler-neck if I try to fill the 2nd-half of the tank using a 5-gallon tank typically used to fill a lawnmower. My old tank, original vent lines, original pump, etc. never had a problem allowing me to fill it to 100% full (at least according to the fuel gauge on the dash) and none of those parts were replaced during the swap.

Tonight, I dropped the replacement tank to take a look around again. Nothing is obvious yet, however I made a few comparisons to my original tank that I still have. Can anyone tell me the purpose of the "ping pong ball" that sits inside the tank's nipple on the filler port? I noticed that my original tank has one that's spring-loaded, however it appears that the replacement tank's "ping pong ball" is not spring-loaded (or is broken). Curious to know if this might be my problem.

Thanks in advance!

Randy

RandyNeagle is offline   Quote Quick Reply
Old 02-20-2013, 10:37 PM   #2
Supporting Member

WF Supporting Member
 
jeepwayoflife's Avatar
 
Join Date: Nov 2011
Location: California
Posts: 3,076
Well the tank is probably full if even the 5-gallon tank cant fill it anymore. This means either the sending unit was damaged when you switched the tanks or it simply isn't compatible with the new (used) tank.

Here's a way to test it. Either drop the tank to get to the sending unit or take out the gas gauge and get to the wires that come from the sending unit. One will be negative or ground and one will be positive and will go right into the sending unit.

Use a voltmeter to measure the Ohms of resistance between the wires that run to the sending unit and ground. With float in up position, resistance should be 20 ohms. With float in down position, resistance should be 220 ohm. If it reads close to 220 ohms but the gauge only reads half, you probably have a problem with the gauge. If it reads something like 100ohms, then the gauge is probable fine and its probably something wrong with the sending unit or the tank itself.

As far as the ping pong ball, I can only speak for chevy sending units, but I assume they are all similar. In my old chevy truck, their are 2 lines on the top of the sending unit. One that feeds the engine, and one thats a vent. The little pingpong ball is on the line for the vent so if gas splashes up (like of you are going up a steep hill), the little ball will plug the line and stop gas from going out the vent. When you are level again, the ball should drop and allow gasses to enter or escape. It is possible you are having "Vapor Lock" in the tank because the vent could be plugged. Again, I havent seen a TJ fuel sending unit before but it should be a similar idea.

__________________
--------------------------------------------------------
jeepwayoflife is offline   Quote Quick Reply
Old 02-20-2013, 11:34 PM   #3
Jeeper
 
Lando25's Avatar
 
Join Date: Feb 2011
Location: Southern Minnesota
Posts: 1,094
Can't really help you out with your problem that much, but I believe the ping pong ball is part of the anti-syphon design
__________________
sic vis pacem para bellum
OlllllllO
Lando25 is offline   Quote Quick Reply
Old 02-21-2013, 06:57 AM   #4
Jeeper
 
C.L.'s Avatar
 
Join Date: Mar 2011
Location: North NJ
Posts: 1,990
You said it was used; are you sure you didn't get a 14 gallon tank from someone? They look identical from the outside, but the 14gal one has an extended internal fill tube that restricts the fill level. The good news is that you can turn it into a 19 gallon tank by cutting the stupid inner tube shorter.
C.L. is online now   Quote Quick Reply
Old 02-21-2013, 10:21 AM   #5
Jeeper
 
cully's Avatar
 
Join Date: Oct 2012
Posts: 100
I just starting having a similar issue also. My tank is empty and i cannot put gas in using the pump, only using a five gallon gas can and it takes forever. Any tips would be great.
cully is offline   Quote Quick Reply
Old 02-22-2013, 09:38 AM   #6
Newb
 
Join Date: Aug 2006
Posts: 10
2000 TJ Sending Unit Replacement

I appreciate all the comments I've received so far. I'm still working on this and trying to sort out my options.

If I need to replace my sending unit, can that be done properly with a stand-alone part? I don't see it listed at NAPA, AutoZone, Advance, etc. however the ebay link below has one...

New Fuel Level Sensor Fuel Pump Sending Unit Jeep | eBay

Anyone have experience with replacing only the sending unit? My pump seems to work fine and this would be a lot cheaper. The discount auto stores appear to only offer the pump, float, sending unit, etc. as a complete assembly.

Thanks again!
RandyNeagle is offline   Quote Quick Reply
Old 02-22-2013, 01:25 PM   #7
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,183
Images: 2
The fuel level sending unit is part of the fuel pump assembly and is tack-welded to it. They are not available separately.

__________________
When you have a choice, buy American.

Jerry Bransford is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 07:33 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC