Won't start after fueling or oil change.

On my 08 CTS last time I got an oil change it the car sounded like it wanted to start but wouldn't. It took about 6 attempts to get it to work. The next three time I've fueled up the same thing happens. And this isn't on an empty tank, I never let it run very low. After fueling it doesn't want to start. Will take 3 or 4 tries and a pump of the gas pedal to get it running.
Once it starts it seems that it doesn't do this again until the next fuel up. I think maybe its the evaporator purge valve? The check engine light is on as well.