Hello I have a 2004 Flex Fuel Tahoe with a 5.3
a couple weeks ago I went to start it after a cold night and it ran for a split second and died. Then it would just crank. Even cycling the key multiple times to let the fuel pump pressure up. It would only start when I pressed the gas pedal down. It would run rough for a second or 2 and puffed a bit of smoke. Then it would run completely fine. It did it again yesterday and today. Only after it sits overnight. Fuel pump turns on and sounds fine. I don’t think I am loosing fuel pressure

 

Welcome to the forum. You need to check your fuel pressure and you need to post in the Tahoe section where you'll get more views.

 

It could be a fuel injector or ignition issue. Check the fuel injectors and ignition system, or have a mechanic scan for trouble codes to pinpoint the problem.