hard starting

[kglowacky]

My LS1 2002 has a hard time 1st starting for the day. Turn key on, let fuel pump run then try to start. It will crank and crank start to spit and flutter then will start after 20 seconds then the rest of day it runs good until yesterday. went to store came out won't start. Crank crank flutter spit but won't start. Towed home. 5 hrs later crank crank sputter sputter then it started. Thinking fuel problem filter or pump. any sensors I need to consider
Thoughts