When I start driving either when the car is cold or warm, the truck hardly responds to the throttle. I can put it to the floor and no acceleration occurs. After several seconds, the truck starts to respond and runs fine. I took it to the Chevy dealer and they said it was due to a gummed up throttle body. They charged $170 to clean it. I drove it home. A few hours later, I took the truck on a drive and experienced the same problem! Any idea what it may be? I am thinking it may be not getting fuel but am not sure. Bummed the dealer charged me to clean TB when that didn't solve the problem. However, the truck is idling smoother as a result. So, it probably needed it.