Faulty Gas/Fuel Gauge

[supranatural]

Ok here is my problem..I filled up my car with a full tank of gasoline but my fuel gauge needle doesn't go all the way up to the "F"..and as I drive my car, the fuel gauge needle fluctuates up and down at times. I have no idea what's happening?? I heard that it may be due to bad ground wires..but I checked and all the ground wires are in tact. The only thing I can think of is maybe my fuel censor is going bad?? I have a new walbro 255 fuel pump and Aeromotive FPR last year. Any help or suggestions will be GREAT! Thanks.

 

[IJ.]

Dead or dying sender or varnish/deposits on the coil part of the sender.

 

[supranatural]

So where is the sender located??

 

[I6Boost]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=92