Dying when started
 

i have a 94 4Runner v6. It runs great and drives great but sometimes when I start it it idles for a second and then dies. When I start it again it idles roughly at about 400rpms but then dies. It’ll do this for 20 mins and then start fine and not have the issue for days. It’s sporadic. I changed the fuel filter and it didn’t do anything. Any idea of what I need to do?