Big overpressure in the gastank

[Allanagtig]

Hey guys!

Im having a big issue with the car atm after its been idling for 10mins or so. The problem is that it starts to go bad and almost chokes itself. I then discovered the charcoal filter began to overflow with gasoline. My next action was then to unscrew the fuelcap and then i discovered alot of vapors were trapped inside as my hair was nearly blown off

I then checked to see if the engine sucked vacuum from the charcoal filter, but it sucked just fine. Im now outa thoughts, but having in mind if it could be something blocking the system ?

any guesses ?

Best regards!

[Allanagtig]

Forgot to mention my car is an coupe ABY from 1993

[quattro-nick]

probably a bad tank ventilation

[Rikki Kitto]

Mine turned out to be a mechanic had connected the flow return pipes back to front

[Allanagtig]

An update to this:

I still have overpressure in the tank and I just checked the EVAP valve and the connector with a multimeter. Ohm value of EVAP valve should be between 40-50ohm according to Audi and the connector with two pins should light a diode when the engine is running.

One question though. The hose from the canister to the EVAP valve still doesnt suck, I was wrong saying it did in the earlier post.
Is there any condition it does so? or should it suck all the time?
The connector shows 12V on all times, but shouldnt it be pulsed?