Fuel tank won't fill past 10 gal.

[jdirty]

so recently i found out that the e30 m42 tank is supposed to be 14.4 gal + reserve? is that true?
if it is then shit. i used to think that i could only get 6+ gal.
which i didn't really pay much attention to because i always smashed on my car. gunning it on the freeway when i can. lol
so i've been wondering..? what could be causing the fuel tank not to fill up?
is there a sensor there that tells it to shut off?
i've tried filling with the fuel nozzle to the side.. and in every direction really.
and my fuel gauge tells me its full.
doesn't really matter with what fuel grade i put in.
i've visually inspected the two rubber fuel lines in under the upper intake and the hard lines too but maybe my eyes aren't that good since there are times i do smell raw gas.

if it helps diagnosing,
in the past 12 months i've replaced the ff:

head
cams (stock)
sprockets
lifters
fpr

fuel filter
fuel pump
charcoal canister delete -plugged it into the valve that goes in the intake boot
put a new cat in

water pump
alternator
replaced ground straps
odo gears
adjusted the ground nuts at the back of the cluster

suggestions..?
i even thought that maybe the previous owner was a drug dealer and tried to smuggle drugs in the car via the fuel tank like that one time i was watching borderwars and thats what the cartel did. lol

[Geoff]

usually when the tank wont fill its a venting issue.  pinched or blocked  rubber vent line is the most likely, I guess.  check the system out on realoem and see if anything seems blocked
                                            G

[jdirty]

thanks for the insight. though I haven't gotten to that yet, I may have found my missing gallons. I went under the car just now an I realized that my fuel tank, on the passenger side, was pretty banged up.

responding from my phone so I apologize for the huge photos

shot from the side


shot from the rear towards the wheel

[Geoff]

maybe you smacked the tenk so hard it crushed a rubber vent hose.  I guess a dent could account for some volume loss but not half of it,  I wouldnt think
                                                                                 Geoff