holley idle issues

If it only does it when the motor is hot then it more than likely is a vapor lock situtation. I just went through the same thing but it was the way I had my line ran that was causing a problem. Make sure you have good fuel pressure at all times hot or cold. The carb will go lean if there is vapor in the lines and it will idle up on you.... mine did. I couldn't figure out what it was until the motor started shuting down in stop and go traffic. Then that's when I started to look real hard on what the problem was. It started out that the carb would not idle down even though the throttle lever was pulled all the way closed. I also wrapped my lines with heat proctection from DEI.