Hard start on 1999 Yukon Denali?

I have a problem starting my truck. It will crank, but just keeps spinning as if if is not getting any fuel. This problem of starting the truck can happen at any time, but usually during warmer months (this has been going on for a while). I could use the truck for a while then get home shut it off and then it won't start again. The problem used to correct itself after literally waiting 5 minutes. Now it seems to be getting worse. When it is running, I never had a problem stalling. The fuel pump was changed about three years ago and the filter was recently changed. When I turn the key I hear the fuel pump making noise as if it is working. I do not get any codes, except once got a P1351. Could my problem be the fuel pump or the fuel pressure regulator, or neither? How can I test the fuel pressure regulator and/ or the fuel pump?Hard start on 1999 Yukon Denali?amazing, i just had the same problem..people thought i was crazy when i said it happened the most when it was the hottest part of the day..and would always start after sitting 5 mins almost to the second, .they finally got a reading on the computer, it was my crank sensor causing the ignition coil to fault..replaced it and we are good to go..(mine did this about 6 months and eventually started shutting off for no reason going down the road..yours may do this too) cost about 206.00Hard start on 1999 Yukon Denali?The vehicle needs to be checked by a knowledgable mechanic at the time when it wont start. Fuel pressure, spark and timing need to be checked at that time.