today i ran her close to empty. in other words i had it in my head that i had plenty of fuel to make it to the station, it was cutting out just a bit on hills and i almost had to coast into the station but luckily i made it. when i filled her up, i could only fit 16 1/2 gallons in the tank. my 94 is supposed to have a 20 gal tank as far as i know. anyone seen where the fuel pump would loose an end fitting or pickup tube and not pump down the last few gallons or do i have the 20 gal capacity wrong? my gauge is off a bit, usually its shows empty but it runs alot when i hit the big E. any info would be appreciated.

thanks ahead of time