makerstr20x

OK so I've got a 2006 with the flex fuel motor. I have always refused to run the E85 fuel because it actually takes more diesel to produce the corn and manufacture than regular petroleum, but that is not the point of this and I don't want to start a fight. The reason for this post is... While on vacation I broke down after being tired of paying 80-90 bucks per tank and filled up with E85. My fuel guage did not move after the needle was on "E". It took about an hour for the needle to "up" to "F". As the tank emptied it went down normal. Since then, when I fill up, normal 10% ethanol blended fuel it does the same thing. Anybody got any ideas? I wonder what the higher percent ethanol did?

JLindsay32

I had this happen, but I use premium, so I don't think it was the E85. On my next fill up it went back to normal no problem... Kinda weird, but what's weirder is that now my gauge moves depending on slope and will slowly go up as I drive. Not trying to HiJack your thread but I believe the answer to this question may help both of us. What regulates the gauge? I'm almost positive it's not a floater, so I don't understand what would cause this.

JeffM8810

Have either of you left your key on / engine running during fill up? Possibly it is the fuel sender going out. If you leave the key on though while filling up it messes with the pcms ability to determine the amount of fuel in the tank and will take a few hours or you may even have to run that tank of fuel out and refuel with the key off.

JLindsay32

I had heard that as well, and I have never left my key on, I always turn it off and put my keys in my seat, (Creature of Habit)

JeffM8810

There is a float in the tank that varies resistance in the circuit which changes the fuel level.

JLindsay32

Really? I thought that was in older trucks, I thought somebody had told me in newer models they are "weight regulated", That's why when you slam on the brakes the gauge doesn't shoot to E because the "float" is no longer used??

makerstr20x

I NEVER EVER leave the key on. I leave keys in ignition if I stand next to the truck to use pay at the pump, but the truck is off. At this particular fill up, I went in to grab a soda and took keys with me. So truck was off, keys out.