Gas gauge goes UP when I press the pedal???

dano said
Not sure about E Body, but on my Dart there is a metal clamp on ground strap from the metal fuel line on the sending unit to the fuel line that is on the body, it basically jumpers the rubber line that connects the two. Do you have this?

Yes, I've actually recently replaced the old ground strap with a new one right when I updated the fuel lines and made sure it's making good contact.

George Jets said
Gas is sloshing to the front of the tank when you let off the gas (G-force), letting the gas sending float down.

Gas sloshes to the back of the tank on acceleration causing the gas sending unit float to go up.

I thought about this possibility, but 2 things: when the fuel level goes down upon decelerating, it will sometimes go all the way down to below "E" even when I have a full tank. I wouldn’t think sloshing would cause it to go down that much. Also, the way the sender is oriented, sloshing towards the front would move the float up and cause a "full" reading, while sloshing towards the back would make the float go down and cause an "empty" reading. So decelerating would cause the gas to slosh to the front and read full, but I'm experiencing the opposite.

I'm interested in testing the voltage theory, and I agree I should confirm I have good grounds.