Vacuum Switch Leak

[dt449]

I have had a fuel leak & after doing some reading I have cleaned the intake valley out,let it dry & checked for leaks (ie:fuel pump,hoses to filter canister,canister drain valve,bottom of filter canister)& cant find anything leaking fluid anywhere (while sitting still running for over 2 hours).But when I run it down the road a few miles & back I find fuel already starting to puddle in the area between the fuel pump & filter canister.Asked a mechanic at the local dealer & he said it might be the vacuum switch located on the fuel regulator on the side of the filter canister.Has anyone ran into this problem with this switch before. Thanks