Rough idle cold

[jljbtm]

This just started in my 99 2500 for the last couple of mornings it starts and runs rough then by the 1st or 2nd stop sign its all better?

I ask myself "what now"

[00Silverado4x4]

TIme for a tune up? Fuel pump getting weak? MAF sensor dirty? Throttle body dirty?

 

Unfortunately there are a lot of things that I think could be the problem. I'd start by looking things over and only replace what you know is bad and if not sure, take it to a trusted shop for diagnoses.

[Duelin]

Another thing that you might have problems with is the CTS sensor. A quick test would be to disconnect and let it go to -40°. And then drive it like that when you first start it up and see if it goes away. Unless you have a scanner and can look and see if your temps. are correct then use that..

[1997SierraSLT]

my 97' would run like crap for the first mile or so after sitting for a few days. I figured it was fuel injection system related since it's a rolling POS that's had the infamous P0300 "random misfire" since the day I purchased it with 17,000 miles on the odometer back in 99'.