I have a 2000 2500 silverado with a 6.0. Truck will no longer start on first crank, usually starts on second try sometimes a third try is necessary. There is real bad bad gas smell when it does start. Sometimes it runs rough for 3 or 4 seconds after it starts. Any thoughts would be greatly appreciated! Fuel filter is fresh, manifold gasket replaced 8 months ago, regulator as well. No codes showing.

 

Welcome to the forum...
What do the spark plugs look like? how is the gap? has the fuel pressure been checked? possible leaky injectors...

 

Plugs are fine.gap is good. Only have 40 k miles on this new motor. What's the best way to check the fuel pressure?

 

There is a port on the fuel rail to plug in the pressure gauge. You can look for a video on Youtube to see how it is done or Google it for a diagram of where the port is.

 

having the exact same problem on a 99 k1500 Sub. Any suggestions?

 

I changed my injectors and the problem is gone!!!