84 Spider fuel smell

[Raybo84]

I know it is an old topic, but I have not found a solution in the previous postings. So I am starting a new one here.
84 Pinin Spider with Bosch fuel injection. Fuel smell at the trunk, vacuum or pressure (I am not sure which) when opening the cap. Funny enough - my fuel smell issue did not start until I replaced all the hoses, including the filler neck hose. By now I have done this twice, double clamped the filler neck, have no visible moist spots but it stinks up my garage. I can blow thru the line to charcoal canister, have a new fuel filter in there and the check valve in the evap line is also open. It shows tank written on one side and is installed correctly. I tried replacing it with a simple connector which did not make a difference. Is it normal that it is open in both direction but with a variing resistance? I also put talcum powder onto all hose connections at the trunk as well as the fuel sender. Now the trunk smells like baby powder but down at the 'new' elbow from the filler neck to the trunk (IAP part) it still smells like gas. Over the winter, the pressure must have dissipated, because the smelling stopped until I drove the car again this spring. There is no rust on the car (OK just a tiny bit) so the rust through of the hardline inside the body is not the root cause. How does the fuel/vapor separator in the trunk work which has the three lines from the tank coming in and is connected to the vapor line to the charcoal canister?
Thanks everybody, Ray.