Lately I have not been driving my Bronco much as I drive a company truck all day, and the Bronco sits all week in the cold. I drove it today after it had been sitting all week in sub freezing temperatures, and with little gas in the tank. After about five miles, the fuel guage started jumping all over the place, going from full to empty and back, all over. I put 5 bucks in it and it got a little better, but still moved from about 1/4 to 1/2. So I filled it up and it seems to be holding ok now. Do these symptoms ring a bell with anyone? It's never done this before.

 

check the archives here and in f series trucks. it is just one of fords little quirks!!.

 

I saw a couple of posts but nothing that defined the problem. Is this something I should fix, or is it something to ignore since filling the tank seems to have fixed it (although it could come back once I run the fuel down).

 

I would suggest it is a Grounding or wire connection problem.

Someone mentioned they had a pin hole in the float and that caused it to stay in the empty position.

Your is apparently moving so, I would think the ground connection is getting worse through rust or corrosion.

Dennis

"Please Don't Ask Me Any Tough Questions As I'm Saving My memory For When I Develop Alzheimer's"

1978 F-150 429CJ 4v,C6 Silver w/explorer package
1968 Mustang 289-2v Sunlit Gold 80,892 miles
1964 1/2 Mustang 260,Pre-World's Fair Car.
1964-Fairlane 500 S/C
Soon to be with a 390-4 spd.

 

Is it grounded at the gauge or in the tank?

 

Also, I am not sure if it is an electrical problem, since putting gas in seems to have stopped it. If it was an electrical problem, the gauge would still be jumping regardless of putting gas in or not.

 

 

Could it be caused by condensation in the tank? I know that can be a problem in cold weather if the tank is not left full.

 

That's sort of what I'm thinking, I kept meaning to put some of that fuel dryer in there but never got around to it. I'll post again if it does this when I run the fuel down, but that may be a while. Hopefully it is fixed. Maybe I'll just have to keep the tank full!

 

I'm wondering if you're not having a problem with in-tank moisture freezing around the sending unit. With the fuel level getting low, the actuator (correct term?) - the piece that the float arm attaches to on the sending unit - would be exposed to the air in your tank, and not submerged in fuel. Is it possible that moisture got into the actuator and froze, causing the arm to stick (i.e. sloshing fuel causing the arm to raise up with the float, and not return immediately, and vice versa.) Just a thought. I'd try some fuel dryer / anti-ice added to the gas (while keeping the tank over half full to keep the sending unit submerged) to see what you get.