rhollister

Just looking for a little help. Got a 01 silverado 5.3. Problem is, first thing in the morning starts great, hit key starts right up, always runs great, stop at station, go in couple minutes, starts great again but once its good and warm and sets anywhere from 10 to 30 minutes you will have to crank it several times before it starts, once it starts it runs great. I have done some forum reading and find this is a commom problem but no real commom fix. I have changed the fuel pressure regulator and just recently pulled all plugs after it has set the 10-30 mins looking for a wet fuel fouled plug, found nothing, Just needing some help where to go next. I am pretty mechanical, have pressure guage, just not sure, Help and Thanks