Fuel Tank Issues! Help!

72DartGuy said
Hi guys, here’s my problem. I have a 72 Dart Swinger with a 16 gallon tank. My fuel gauge shows really full for a couple of days, then at 1/4 tank it starts to “run out of gas” I go to fill her up and she takes 6 gallons every time. I’ve got 10 gallons that I can’t get to! Anyone know the fix? My sending unit is good and I just took the filter off if the pickup because it was getting sucked up and cutting off my fuel, lmao! What do I need to do to get to the bottom of the tank?
Thanks everyone, and thanks FABO!

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Okay, let's start at the beginning.
You're saying you have 10 gallons left when the sender is on "1/4". And it registers "Full" for an exceptionally long time.
You have a float issue.
When installing a new sender/pickup (especially some of the new repro ones of dubious quality) it is imperative that you check and adjust the float sweep if necessary. this involves nothing more than bending the arm of the float.
To do this, you need to remove the tank. Install the new sender, and using a flashlight (not the old joke about using a lighter) look in through the fill tube hole and see where the float is. If necessary, reach in with a coat hanger and move it to make sure it can move up and down unobstructed. In your case, I'm going to guess it comes to rest about mid-tank. It needs to come to rest maybe 1-1 1/2 inches from the bottom (just so you've got a bit of "reserve" in the tank when you hit "E"). make a note of how far you'll have to adjust it, and remove the sender again. Now bend the float rod downwards the amount you you've noted, and check that the float arm still moves up and down freely. Reinstall the pickup and check float operation. Readjust if necessary.
The pickup tube should be at or very near the bottom of the tank. Adjust if necessary by bending the tube. Do NOT run it without a filter sock. I understand the sloppy fit of some of the available pieces, all you need to do is put a small stainless steel hose clamp, or even a short piece of snug-fitting fuel hose, on the tube in such a location as to prevent the sock from being able to slide up the tube enough to block off flow. Some aftermarket socks even have a small flat area on them to be able to clamp them directly in place.