I've been storing the Stang for the winter and I went to add a bottle of Stabil in the tank (only 50% full, WOOPS. I didn't get a chance to fill it up before the first salt hit the roads). As soon as I opened the gas cap, I heard the gas gurgle down into the tank, as if some of the gas somehow traveled up the filler neck and got stuck there due to vacuum in the tank or something similar.

Has anyone else noticed this with their stored Mustangs? Is this a sign I will have the slow to fill problem? I've never filled up the tank yet, and no it's not a Paris Hilton thing
Or should I expect spider egg sacs in the evap system fresh air intake hose?

 

I haven't noticed that ever happening, but I have the most difficult time filling mine up with gas. Either it will start spitting gas back at me or the pump will just shut off like it's full, when it's not. I'm not so sure I like the gas tanks in these things. Oh the other thing my car does is, when I bought it I used to be able to fill my car up and consistently get it to read around 320 miles till empty, now I'm lucky if I can get it to read above 300 consistently. Something is screwy with these gas tanks. If anyone has any input on this let me know.

 

I think its definitely a filler neck issue because the only reason i could think of explaining my gas tank "gurgling" as soon as I opened the cap, is that gas stayed there coupled with changes in pressure forcing the gas to remain in a vacuum. It could also explain why the gas pump nozzle will cut off early or spit gas back at you, since improper routing of the fuel could result in a pressure buildup with the high pressure nozzle. Looking at the FSM, the fuel filler neck/tube is a narrow tube routed in a maze. On the trucks and Crown Vics, the filler tube is a large and straight tube that dumps straight down into the gas tank.

I'm guessing here, but a larger diameter filler tube ought to fix the problem once and for all.

If I heard a HISSING sound as soon as I popped the gas cap, that would signify a kinked vent tube, blocked vent, or a clogged evap system air intake hose (been there, done that before... it will set off a DTC).

 

I'ts the way that you drive your Mustang as well just the engine running at a stand still , now if you disconnect the battery wait a few seconds rehook it up , you will here a short alarm beep, that's ok then you will have to reset your clock & AM staitions the CD will automatically Initialize itself you will here that, Then go look how far you get per tank, I find this helps me to BEHAVE more often to keep up how far I can get on a tank.

 

Interesting