So ever since I got my car last year, I have been having trouble filling the tank full. I put the pump on automatic like I would with any other car, but once it starts to shut off automatically it shoots gas back out all over my bumper and valance. It's not even close to being full when it shuts off. So then I start filling it manually, with barely any pressure on the lever so I can control the flow.
I can watch the filler neck fill with gas, so I stop the flow. Then the gas is sucked into the tank, it makes that gulping/swollowing sound. It's like there isn't air getting into the tank when I fill it, causing it to overflow.

So my question is, how do I fix this overflowing problem? Also when I do think it's all the way full I turn the car on and the gauge only reads 3/4 full. The guage never goes all the way full. So I filled up at 1/4 tank tonight and I only put in 6 gallons because it was doing that overfilling thing and I though it was full, but again the gauge said it wasnt. Whats the problem here?

 

I am also smelling gas fumes in the trunk area all the time. The rubber filler neck connector looks new so I can't see how that would be the problem. There arent gas leaks anywhere that I know of. Any other ideas?

 

tank might be rusted it is the trunk floor! try turning the nozzle sideway and pulling it out a little bit

 

Do you have the kind of gas pumps that seal around the opening? if so insert the nozzle so that it does not seal. rmodel65 hit the nail on the head. For whatever reason my '66 fills best by turning the nozzle sideways too. They used to sell a coiled spring you could stick in your filler neck, so no one could siphon gas. Kind of made it a pain in the rump too. check and see if you don't have something like that in there.
It hurts enough to go to the pump in the first place. Aweful hard to watch that liquid gold spill back out!
Good luck,

Scott

 

yeah u should of seen the look on my face when my dad is standing back there with a big grin thinking to himself "Ahhh, what a glorious sunny day!" and the gas is just pouring out of the filler neck all over the ground.....NO BUENO!

 

i have the same problem on my car, you just gotta take your time fillin the damn thing up.

 

ngirg001 you're right, I have to take my time and I always get a full tank. If I'm nearly empty then I can stuff just over 20 gallons in it. Just can't be in a rush.

 

I had that gas smell in my trunk a few weeks back, and figured out it was the rubber hose on the filler neck that had a tiny crack in it. I also replaced the gasket on the gas cap. That solved my smelling gas problem. Also, check around the sending unit. That gasket may be leaking. And, pull the trunk liner up and see if you may have a pin hole in the top of the tank.
When my tank is absolutely completely full, my gauge only reads 3/4 full too. I don't worry about it though. I just drive it until I reach about 1/4 on the gauge, then it only takes about 6 gallons to fill it. That's just one of the ideosyncracies of these old Mustangs.

 

Ya I read that thread of yours Soaring about the rubber hose, thats why i suspected it. Well now I feel better that you guys are having the same troubles, just wanted to make sure it wasnt just me. THanks!

 

My 68 used to do the exact same thing. Perhaps its the way the hose gets to the tank when the caps in the back middle?? I got no idea, all I know is you could not trust the auto shut off at the pumps. You just had to look at how much fuel was left before you stopped then put in that many gallons. I never filled it up so much that it was in the filler neck, that could be why you smell gas in the trunk, just from gas sitting in that neck there might be the smallest little bit working its way out.