03' 1500HD / 6.0 / 190K Miles
This problem started out the blue and I cant figure it out. No matter when you try to start the truck it will turn over and over until you stop. After the 3rd try it will crank right up and run great. No other issues, it runs like a champ but its guaranteed to take three tries of about 5 seconds each before it fires. It does this Hot or Cold. No ruff idle, no skipping, no nothing other than the hard start. What gives, any ideas??

 

Sounds like you are lossing your fuel prime..........put a fuel pressure gauge on it and try to crank it and check the pressure....either that or the oil pressure sensor for the computer is bad (long shot)