my 2000 sierra with the 4.8 is having a hard time starting in the cold, its all stock other than exhaust to true duals, it starts and almost dies 4 or 5 times and then runs just normal from then on, maybe a choke problem?

 

Definatly not a choke problem...lol

Do you have a SES light on? Could be a PCV valve, o2 sensor or something small like that...go to autozone and have them scan it for and DTC's, they do it for free..

 

mine did the same thing take it to the advance and have them check your batt/alt.

 

Does the truck crank slow? If so, may be a battery problem. If it's cranking OK, first things that come to mind are possibly a dirty or faulty IAC valve, fuel pump that is on it's way out, or possibly bad gas. There's a ton of different things that it could be, these are just the first that come to mind. You could try cleaning the throttle body and IAC first and see if that helps...

 

battery can cause this..seen it happen to a 03 z71 that came in doin this..boss stuck a new batt the guys truck and never happend again

 

Have the battery checked out first. Would look at the fuel pressure regulator next.

 

Does it run roug for a little bit? Reason is we see a bunch of upper intake gaskets leaking when its colder outside. Warms up and gaskets seal off. We
our doing a bunch at work right now...

 

It might have something to do with your oil, make sure its 5W/30 for cold starts.