I need some help before winter is here. My 2000 silverado 5.3 doesn't idle when it is cold, 20 degrees or less . i have to keep my foot on the throttle till its warm. once it has been warmed up its good for the day. any ideas would be much appreciated

Cheers

 

Was the throttle body bypassed?

 

No, its completely stock, 150,000 miles