Our 2005 Suburban cranks longer than before. If you tickle the peddle it starts. She has 70k miles on her & runs smooth otherwise. She's averaging 17mpg. I do add 3 ounces of Lucas fuel injector cleaner to the tank every 90 days. What could be the trouble? Could it be; plugs, throttle body dirty, clogged fuel injectors, vapor lock, all of the above...what? Where do we start? We have done zero maintenance besides oil & filter changes.

 

Might try cleaning the throttle body and associated idle control.

 

Check for codes. Tickling the pedal has nothing to do with starting. That is not a carbureted car. I d guess if you didnt touch the pedal it would start easier.