Excessive pressure in gas tank?

[TheMaxx]

Alright I'm sorry if this a dumb question or has been asked before but I could not find anything in search.
When I remove my gas cap to fill up you can hear pressure from the tank bleeding off and even feel a little bit of force behind the cap. I was reading one thread saying that you need 2psi of pressure in tank this would seem a little bit higher then that. Is this normal? Also I can smell unburned gas while I am driving however my CC purge side is not hooked up to my BVSV as I realized after I bought the car it had both nipples broken off, and what appeared to be shoe goo holding the vac line's on. I'm very skeptical it was actually doing anything like that.

 

[planemos]

BVSV always get broken. I think drifmotion has them. Or try and find one somewhere. I wouldn't worry about the pressure in your tank. And if there was more than 2psi, trust me you would have no doubt that it was more. Of course you are going to hear and feel a slight difference between atmospheric pressure and atmospheric pressure+2psi. Just make sure everything is hooked up right and no leaks. You wouldn't want a fuel fire in your car.

 

[TheMaxx]

As far as I can tell the only thing leaking is my rear struts..

Thanks for the help.

 

[PROTOTYPE]

IIRC, I saw a guy on here that had same thing going on and changed his fuel cap and solved his problem. I found it odd but I have heard of it before working on other makes. Honestly I haven't worked with Supras long enough to know their emissions style. When I think of excess psi in fuel tank I start leaning toward vent/closing valves. But then again I hate saying anything without seeing the car for myself.

 

[hvyman]

If the charcoal canister is not Hooked up you need a vented gas cap.

 

[jetjock]

^ If the evap line is capped he does. As for not worrying about pressure I remind people a small delta P across a large area can have as much force as a large one across a small area. It's not just about pressure.

 

[PROTOTYPE]

If the charcoal canister is not Hooked up you need a vented gas cap.

I'm not sure if that was aimed at me or the OP. I am aware of that. The person in reference had everything hooked up like stock, and needed a vented cap. I think something else was wrong and that's a band-aid for his underlying problem.

 

[TheMaxx]

If the charcoal canister is not Hooked up you need a vented gas cap.

My CC has all lines too it but the purge side is just a hose that I left lying on the fender well as my BVSV is broken, does the canister need to hooked up too the BVSV to function?

 

[destrux]

http://www.autoshop101.com/forms/h62.pdf

Take a look at that. The 7M uses a system like the one pictured at the very beginning of that article. Hope this helps you figure it out.

 

[TheMaxx]

Destrux I believe that is what I needed to answer all my questions

Thank you very much sir