Smells problem
1986 Mercedes Benz 560sl V8 Two Wheel Drive Automatic 11277 miles

I recently purchased a 1986 560sl that was sitting 4 years i removed gas tank and had it cleaned after reinstalling car runs fine however when i remove the gas cap there is alot of presser and fuel pores out of neck i also replaced 3 gas cap and the same problem happens.any sugestions to maybe a venting problem.Thanks Glenn