Has anyone experienced pressure building in the gas tank? Had a tech rebuild my Qjet and when he undid the in line at the carb, fuel kept pouring out,until he undid the gas cap and the whoosh of pressure release sort of surprised him. This is a 1980 , 305, w/mechanical fuel pump, and I can't recall in the past ,pressure buildup in any other veh I have had. Since then, I leave the cap loose until I find the solution.
My questions being, is there some type of one way valve in the return lines and where would they be located?Could this possibly be result of any blockage in the cannister located in the left front area under the hood? I also notived just yesdterday, a fuel odor for the first time, looked under the hood,under the car and around tank,pump, found no indication of any leakage or damp spots.
Any ideas or clues?

I agree with your thought that it is a blockage in the vapor cannister. I had a similar problem with gas tank pressure which was preventing me from filling my tank, the pump kept shutting off. I replaced the vapor cannister and no longer have a problem.

Also check for a kinked hose going to or from the vapor canister--or call it primitive fuel injection??:dontknow: Glenn

Also check for a kinked hose going to or from the vapor canister--or call it primitive fuel injection??:dontknow: Glenn

Yeah, I like that. Just hook that line to a fuel injection manifold. We won't even mess with a computer.

Doug

When my '74 did that, I had pluged the vent line that goes to the canoster.
:buttkick:
Cost me a new tank. It went :blowingup:
Bad :dontknow: