V6 Erratic Fuel Gauge, any advice?

Discussion in '2005 - 2014 Specific V6 Tech' started by CalPolyStang, Aug 1, 2008.

  1. I own a 2005 V6 mustang. I have kept it stock due to lack of funding. Since I bought the car three years ago, there has been an issue with refilling the fuel tank: when I go to refill, the sensor on the pump will shut the pump off early (after a gallon or two... never consistent when it shuts off, sometimes its after only about .2 gallon) even though I know I have an empty tank. This wasn't really a big deal because I always knew roughly how much gas I needed. All of the forums simply stated it was an oddball, un-fixable and overall simply inconvenient error.

    However, about 8 months ago, my fuel gauge suddenly registered at below empty. At first I thought someone had siphoned my gas but I have a locking fuel door and it had not been tampered with. After a few times of turning the car and and off, it began to register again. Over time the fuel gauge would become more and more erratic, most of the time registering at empty or below the E line. I finally saved up enough cash to take the car in to a mechanic. He thought it was the sending units, so he replaced those. Still no change. He's contacted Ford and a few other resources and is unable to find the error. I have checked all the forums and so far, I'm unable to find any repair options aside from "replace the sending units." I'm uncomfortable taking it into Ford and have them charge me up the wahzoo and in the end say, "sorry, we don't know what wrong." I've been working off of the trip odometer, but it still concerns me as I am constantly on the move and need a more reliable fuel gauge so that I don't end up stranded somewhere. I also don't want the other gauges to go out on me and end up SOL.

    If anyone knows of any solutions or other resources, please let me know asap. Thanks in advance!
  2. Filling the gas tank issue is generally fixed by replacing the tank. Has Ford done that? I don't know abou the other issue.
  3. I had errors start popping up FLI DATA ERROR, FUEL LEVEL LOW and the gauge would drop to empty. I went to Ford and they said it needed new two new sending units at the cost of 455usd. After they did the work it took a long time to for the gas gauge to move up to the correct position (like 30 minutes) when filling it up. So I went back and they said maybe it was the instrument cluster, but when they said maybe I walked out.
    I drove it for three months like that then one day I decided to over fill my tank (thinking that is what might have started the original problem) and low and behold that some how fixed the slow gauge problem. It works fine now.
    But I will tell you what will piss it off is turning on the key and try to watch the gauge when filling the tank. it will stick then I had to run some gas out then fill it up and it fixed again.

    Back to your problem, My theory is it'seither sending units or the instrument cluster. :)
  4. i found when fueling if you flip the pump up it fuels ok, no problems since i did this.
  5. Yeah, I come across stations that are a little too sensitive and I just flip the nozzle upside down so I can go full blast.
  6. I have had the exact same problem. I have had difficulty filling the gas tank of my 2005 V6 mustang, and subsequently found that holding the fuel nozzel tilted about 90 degrees while filling allows gas to flow into the tank unhindered. Additionally, I started noticing erratic behaviour of the gas gauge on the dash, reading empty when I had just filled the tank. Fortunately, the underlying problem caused the check engine light to come on. The code read as a bad fuel sensor, I have yet to get this fixed since I just got the diagnosis a week ago. I was planning on going by the trip odometer until I get it fixed... will cost $600-700 for parts and labor. My symptoms sound identical to yours, so I think you should have them check/replace your fuel sensor. Hopefully this helps even though your post was over a year ago.
  7. Unfortunately, with ethanol being blended into today's gas....there's little that can be done other than asking if the replacement pump or sensor is compatible with ethanol blended gasoline. Also not letting your tank go below half will help prevent some of these erratic problems due to condensation absorption by the ethanol.