Hey guys,

Finally got my '64 Belvedere on the road (and strip) this summer. For the first few months, the gas gauge worked perfectly with a normal needle sweep. Then one day, a full tank began showing as "half tank" on the gauge - the needle straight down. From that "half tank" position, the needle seems to sweep normally to the left as I burn fuel. A true half-full tank of fuel shows the needle on "E", and an empty tank will place the needle to about the 8 o'clock position, far beyond and above the "E".

I have noticed that when filling the tank, the needle moves from the left to the right normally until it gets near the half tank mark - then the needle begins to jump and skip. The car has a new tank and sending unit.

Any ideas? And thanks ahead of time!

Sending unit?

Sending unit or ground. Check the metal piece that couples the gas tank outlet to the metal fuel line. May not be making good contact anymore.
Craig

Float is leaky causing it to be heavy, or as previously mentioned,bad ground, or bad rheostat on sending unit.

I would confirm the ground is good with a jumper all the way up front to the batt neg post (get the gauge in the offending area & see if this ground wire changes things) but with it only acting up half the time it & appearing to be good the rest of the time it sure sounds as said like a rheostat winding prob (& sender needs to come out). First I would ohm it tho at several positions just to see what you get