Hey,

I figured this might be a TPI post.

Either way, i've had evap problems with my car ever since I bought it. The relief valve at the tank was replaced with a new one, new charcoal canister, new purge valve, new vacum valve that sits on the tank line coming to the canister.
My problem is, once I get about half tank and its above 60degrees outside the dang evap line gets gas in it and shoots it into the TB making it run rich. I am not sure how to get rid of this. I tried unplugging it and I can hear the damn thing gargling, girgling (how ever ya wanna spell it) through the line. Once I relieve the pressure by unscrewing the cap the gargling stops.
I am at my wits end with this p.o.s. The car failed emissions 7 times because of this, and the mechanics (previous owners mechanic) thought that plugging those lines with rods would solve the problem. It did for emissions, but not for my pump which whined until I figured out what the problem was.
I need some suggestions other than replace this, and replace that.
This car is a fighter, i tell ya.

 

Is it possible that the fuel return line and the vapor line got reversed ????

Vapors are usually drawn from the top of a tank. Fuel return would be father down.

 

I'm not sure if its a similar situation but my 87 TPI was doing the same thing. You could even hear gurgling in the gas tank. I thought there was a pressure build up so I did the same as you. New tank vent valve, fuel vapor canister, purge valve and nothing would fix the problem. I checked to make sure none of the lines were reversed or routed wrong and also to make sure i had the correct vapor canister for that year.

I finally fixed the problem with a new fuel pump. How did I know it was the fuel pump? Well i tested the fuel pressure with the car running and it held steady. Then I turned off the car and watched the fuel pressure. After about 30 seconds my fuel pressure started to bleed off. This meant my fuel pump was bad because of the internal one way check valve inside the pump was trashed.

I don't know if this is your problem or not but it could be similar and the test only takes a gauge and a couple of minutes to test. Only down side is that replacing the pump is a major pain. Let us know when you figure it out.