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Discussion Starter #1
The gas tank and sender are about 3 years old. I changed the gauges to Auto Meter Phantom. I've been struggling with the gauge reading and switched between Linear and Non-Linear. But ran out of gas a couple of times and was only able to put in about 12 gallons at the most with gas spilling out the neck.
I've been measuring the ohms on the sender and noting the gas gauge and how much gas it will take. I data fits for a Non-Linear gauge. But I can't seem to be able to use the last of the gas, the gauge will show around 1/4 tank and it'll die until refilling.
Has anyone had a problem with the filler tube being bent? That's the only thing that makes sense. I'm trying to find a solution before draining the tank.
 

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I've never personally heard of the pick-up tube being bent somehow inside of the tank. Anything is possible in 50+ years though.
I have heard of the pick-up tube being damaged by rust and other problems, mostly associated with age. The only way to find out for sure is to crack it open and have a look.
One way that you can diagnose it without going into the tank, is to disconnect the fuel line from the suction side of the fuel pump, after the engine has run out of fuel, and see if you can siphon the remaining fuel that is inside of the tank. If you can get fuel to flow from the line, then the problem is likely the fuel pump not being able to pull the fuel from the tank once it drops to a certain level.
 

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Discussion Starter #3
That's a good alternative to dropping the tank initially. The only other thing I can think of is if it's forming a vacuum since there is no venting.
 

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The fuel tank must be vented somehow. If the tank itself is not vented, then the fuel cap must be vented.
I can't remember what kind of fuel pump that you have... Is it mechanical or electric?
If it is electric, is it mounted somewhere near the fuel tank?
 

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Discussion Starter #6
It's a mechanical fuel pump. It' a factory replacement style gas cap, not a 3rd party cap. So I'm sure about it being vented, it doesn't look like it is.
 

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I would think that if the problem was caused by the fuel tank venting, that it would develop a vacuum easier with a full tank of fuel, and less air in the tank.
 

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Discussion Starter #8
I would think that if the problem was caused by the fuel tank venting, that it would develop a vacuum easier with a full tank of fuel, and less air in the tank.

I agree, but it still makes no sense. I looked at the bottom of the tank and it is flat and not mashed up concave. The pickup tube is the only thing I can think of that I haven't looked at.
 

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I've had problems with my gas gauge too. I remember seeing something from autometer saying for our mustangs we need a different gauge ohm range than what factor called but can't remember now ill try to google it. Also, another thought would be if the sender unit was not in the right position (with the float vertical) it could give you an off reading.
 
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