hard start up

ok so i recently got a 2001 gmc safari van for a daily driver. im having some problems starting it lately. it will turn over and crank fine but wont catch, and it only does this once its been sitting for a couple hours. Once its running it runs fine and will stay running. After being ran for a while it will start up fine too it only acts up when it sits for a bit. I changed the fuel filter which helped it a bit but still takes some cranking to get started once its been sitting. Any ideas on what else to check?

Fuel pump may be going bad. Try priming it first and see if that changes it.

Yep, fuel pump.

Don't listen to everyone else. They're wrong. It's actually the fuel pump.