I have a 99 silverado with a 4.8, I do not have a check engine light or any codes in it, But everytime when we go to start it and drive off it hesitates and bulks and doesnt want to take gas, But this is only when the engine is cold! What could this be? Like said I do not have a light on or any codes found in it, Could it be the temperature sensor for the computer causing this? Thanks guys for any info