Fuel Tank Venting - BASIC

["Ree Gurley" <reegurley@mindspring.com>]

When opening my fuel filler-cap, I get a major SWOOSH of air going in.  Am I
correct in assuming that this swoosh is NOT desirable (and indicative of
some blockage in the canisters/lines/restrictors/vapor separator)?

Ree G. in Silver Spring, MD  -  78 Spit  FM73070U O