fuel tank problem

[TheDon]

ok here is the skinny

i put 6 gallons of D2 in yesturday .and raised the level from almost on reserve to almost half full

drove 80 miles and its down to 1/4 the capacity of the tank is 21 US gallons

shoudnt the 6 gallons i put in not of registered at half tank? unless im not doing my math correct

i can tell you that the tank has a vacuum on it because when i go open the filer cap air rushes in. i need to unclog the vent i suppose if that is causing the problem.. could my tank have a dent in it perhaps? is the only way of making sure is by un hooking all the fuel lines with an empty tank and visually inspecting the tank . and i think i need to turn the alda back a little


**just tried to move the alda back a little and .. i uhh broke the set screw.. wonderful o very wonderful. no other change.. why cant diesel go back down to 1.20.. why o why. damn arabs***