when i start the motor in the morning it idles rough till i hold down on the gas on 1991 Chevrolet S10

it has been doing it more often it idles really rough step on gas a little then it will idele better runs really good just does it after it sits awhile or over night

Asked by for the 1991 Chevrolet S10
1 answer
you may have carbon build up in throttle body or idle air control valve is bad