Weird starting problem

[KrustyCraftsmen]

The ONLY time this happens is directly after i put fuel in my truck, no other time. when i fuel my truck i get back in and its hard to start, sputters rough starts then cuts out, then i try again and it starts perfectly fine. no idea why it does this wondering if anyone has had this happen before.

[RyanbabZ71]

http://www.gm-trucks.com/forums/topic/194464-hard-start-after-fueling/page-2?hl=ryanbabz71&do=findComment&comment=1899976

[muddkatt]

Purge valve is bad.