Always full of ........... gas

Mac2Night · Dec 5, 2006

Okay, I've searched the archives and not found my exact problem so I have to ask:

Why does my gas guage always read FULL, even when I've run out of gas in the middle of a busy intersection at rush hour (yes, it happened to me yesterday morning and I was in it deep)? I've not investigated because I've only owned the truck two weeks and thought I was getting GREAT gas milage out of this 33 year old V8!

Thanks,
Mac

bronko69er · Dec 5, 2006

Full reading means low resistance. 10ohms full, 70 ohms empty. Maybe the sending unit has a short to ground?

Skuzzlebutt · Dec 5, 2006

How are the Oil Pressure and Eng Temp gauges working? Is the problem isolated to the Fuel gauge?

Mac2Night · Dec 5, 2006

Yeah, it's just the fuel gauge. Temp, oil and volt all seem to operate fine.

One thing that I noticed tonight getting out of the truck that I noticed the first couple of days I had it though...... when I go to get out of the truck I feel a slight shock of voltage when I open the door (touch metal). If it is a poor connection would that do that and where would it be coming from?

Skuzzlebutt · Dec 5, 2006

The shock is wierd. I've no idea what would cause that.
RRRAAAYYY might have a clue. I can't imagine it being related to a gauge though.
If there is a short in the fuel gauge circuit the reading would be pegged noticably higher than the full mark. If it's at the full mark it's probably the sender in the tank is sticking, not letting the float move up & down with the fuel level.

70_Steve · Dec 6, 2006

Mac2Night said:
One thing that I noticed tonight getting out of the truck that I noticed the first couple of days I had it though...... when I go to get out of the truck I feel a slight shock of voltage when I open the door (touch metal). If it is a poor connection would that do that and where would it be coming from?

Static electricity. You don't feel it so much on the newer cars because they're all plastic. This is still all steel.

Do you have two tanks, and a selector switch on the dash to switch between the tanks?

Crawl under the Bronco and find the fuel level sending unit. There's two wires plugged into the sending unit. Pull off the connector to disconnect the sending unit. Turn on the key and see if the level now reads empty. If it does, then the problem is in the sending unit. If it still reads full, then the problem is in the wiring between the gauge, and the sending unit.

Mac2Night · Dec 6, 2006

Thanks Steve 70. I don't have 2 tanks or the switch (this base model was ordered without the aux tank option).

I'll try pulling the wire tonight. I pulled the wire off the back of the guage cluster last night and the needle dropped to empty. The needle normally stays just under FULL/not at FULL or over, but of course I just filled the tank up yesterday due to my running out of gas the day before.

Thanks for all your help.
Mac

scottmcwms · Dec 6, 2006

Sending unit sounds stuck. You might need to run some varnish remover through the system. SeaFoam is a great varnish remover. The varnish might make your sending unit to stick. When you are up under the Bronco checking the wiring as stated above, shake the fuel tank vigorously and see if you can break the sending unit loose.

MarsChariot · Dec 6, 2006

Or, as stated above, there could be a short between the sender and the gauge. It can happen to any of the gauges. I was tooling along at 55mph next to the Salton Sea one hot summer afternoon once when the oil pressure gauge suddenly pegged. A quick stop revealed that the wire on the sender had frayed, fallen off and was laying, fully grounded, on the oil filter housing.

twisted_mr · Dec 11, 2006

I would think if the sending unit was stuck in the full position that a ride down a real bumpy road might cure the problem. Can't hurt anything anyway.

Broncobowsher · Dec 11, 2006

Unhook the wire off the sender (at the tank), turn the key on.
Gauge reads full, wire has a short to ground.
Gauge reads empty, sender is bad.

Always full of ........... gas

Mac2Night

Bronco Guru

bronko69er

EB Addict

Skuzzlebutt

PhD, Dr. of Broncology

Mac2Night

Bronco Guru

Skuzzlebutt

PhD, Dr. of Broncology

70_Steve

Old Guy

Mac2Night

Bronco Guru

scottmcwms

Sr. Member

MarsChariot

Planetary Offroader

twisted_mr

Full Member

Broncobowsher

Total hack

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