2004 sable sometimes wont start in the morning

I have 04 sable that wont start in the morning when it tends to get a little chilly. I am not sure what is causing this. two of the times it would not start I pulled off the fuel line and had no gas one time and a little bit the next time then when I put the fuel line back on it just starts up. Just wondering if anyone has seen this problem before.

Thanks