My 93 del sol supposedly has a 11.9 gallon tank, but ever since I've had it, filling it full puts the needle just under the full mark and driving it to "empty" leaves the needle a bit above the E mark. Funny thing is, when I fill it up "full" only about 9 gallons goes in from that E mark. (the car also hesitates to start at this E mark because there is such little gas...I assume). What am I missing here?

Fuel pump?
Fuel filter?
Fuel floater?
Cluster problem?