So here is one that I just can't figure out. My fuel gauge reads full when full, goes down at what appears a normal rate but when I am on empty and go to fill my 15 gal tank I get 10 gallons in at most. I thought it was my sending unit and figures what the hell, it is better than thinking I have more gas than I do so I stop more often but I never run out of gas. Well, last week I put in one of the new Holly intank fuel pumps and sending unit combinations. I have fuel injection and needed a new pump. I thought, this will definitely solve the gauge problem, but its acting just about the same. Has anyone experienced anything like this? Could it be the actual gauge in the dash? Seems weird to me that two sending units act the same and I am positive I have a 15 gal tank not a 20 gal tank with the wrong sending unit. Any thoughts are appreciated.