replaced the temporary elbow with new vent valve...gas fumes strong as ever...

I am stumped...as there was almost no fumes at all with the elbow in place instead of the vent valve, I can only assume that the pressure build up in the tank is causing a leak somewhere in the tank itself. We have removed the tank twice and pressure tested it, with a special cap to seal the tank...plus the tank always seems to be under pressure when we remove the fuel cap after running..so it would seem that the tank integrity must be ok.

Summary of symptoms


gas fumes in cabin when getting in the car first thing in the am..car cold...gas odor is slight but present.

strong gas fumes come in the car when driving but only with window cracked...no fumes when using heater with fan on, or fresh air vent blowing

no visible gas leaks under car when sitting (now)

at one point there was an apparent liquid fuel leak because I did have a visible fuel leak under the car. However since tightening all fuel lines, there no longer appears to be any live fuel escaping when sitting..have had the car on a lift multiple times...fuel was running down the fill pipe, then down the outside of the tank and collecting under the rubber at the bottom of the tank...this no longer appears to be the case, as it has always been dry the last few times we put it on a lift. This fuel appeared to be coming out of the fill port, and leaking by the rubber grommet that seals the fill pipe from the frame...however when we pull the car in after test running and having fuel odor, and inspect the fill port, there is no visible sign of fuel escaping..no visible wetness in the fuel fill chamber either

no gas odor under hood with hood open

Have done the following:

changed gas caps at least 4 times with new caps

smoke tested entire fuel system with everything in place..no obvious leaks

removed fuel tank twice and pressure and smoke tested it..no visible leaks

replaced carbon cannister

replaced vaccuum lines to carbon cannister

pressure and smoke tested lines from tank to carbon cannister

replaced purge/regeneration valve

checked eha for leaks multiple times

replaced vent valve

tightened fittings at strainer and fuel pump (or was told that was done)

Am stumped...thought we had it licked when we replaced the vent valve with an elbow and fuel odor stopped...figured bad or sticking vent valve...maybe still true....

We found loose carbon had plugged the line from the cannister to the purge/regeneration valve (the one inside the fender), as well as the valve itself..Although we tested it for flow and it seemed ok, we maybe have carbon in the vent line(goes from the tank to the carbon cannister),Maybe we have residual carbon in this line which got sucked back into the new valve causing it to stick too? Will open up the old valve to see if any carbon in there, then blow out the vent line to see if any carbon comes out. If I find any, will replace the two way vent line, as well as the new valve.