I have a 1999 Blazer with a V6 Vortex engine. Some mornings it starts right up with no hesitation. Starts just fine the rest of the day. Other mornings it will crank and fire briefly before sputtering out. Starts just fine the rest of the day. Other mornings it will just crank and not fire. After about 15 tries it will then fire right up and start fine the rest of the day. It's very sporadic. Maybe 1 morning out of 10 it is difficult to start. Weather doesn't seem to matter. It's terribly frustrating.

 

Sounds like possibly a fuel pump. Get loaner fuel pressure gauge from local auto parts store and catch it in the act. Key on engine off - will pulse fuel pump 2 sec when key is first turned on. Should be 58 psi or more after the pulse (not necessarily 60) and should hold the pressure for a significant amount of time afterwards if the engine is not cranked or started.

Your reference will be the fuel pressure sticky at the top of the 2d gen forum. Have a read. If you have a problem during/after the initial pulse, then do all four tests as described in the sticky and report.

ps it's Vortec not Vortex