2000 blazer hard start after sitting or humid??

Hey guys i am looking for some answers. My blazer was running like crap got a po300 code. I did a tune up ran great for 3 months....then started hard starting when humid. So i changed EGR and Coil. Ran great for 3 days started same crap again.....getting frustrated. normally after cranking a bit it would eventually fire. This time however it will not. any ideas? I hear the fuel pump running....seems like a spark issue where do i go?
http://staticaf.com/vbulletin/images/smilies/banghead.gif

What did the tuneup include?

Is it hard starting more cold than hot?

Hey guys i am looking for some answers. My blazer was running like crap got a po300 code. I did a tune up ran great for 3 months....then started hard starting when humid. So i changed EGR and Coil. Ran great for 3 days started same crap again.....getting frustrated. normally after cranking a bit it would eventually fire. This time however it will not. any ideas? I hear the fuel pump running....seems like a spark issue where do i go?
http://staticaf.com/vbulletin/images/smilies/banghead.gif

Did you replace the Distributor Cap? P0300 Codes are almost always in the Dist Cap. Replace your cap with an AC Delco Cap only.