I have a 92 civic and for some reason whenever I get below a half tank I can never get an accurate gas reading. It will go up and down depending on curves, hills, etc. Anyone have any ideas on how to fix this?

 

Just wait till your level again then read your gauge....

Theres nothing you can really do, when you go up or down hills the gas will be at an angle in the tank and will read differently. Going down usually says it's slightly more full, going up slightly less.

 

Yep, the tank is not perfectly shaped.
Nothing really wrong with it
Now if you go and fill up and then your gauge is still going up and down, or not even reading a full tank, then yes, you have a problem.