Seems when the engine gets warm, it starts to misfire.. not transmission. on 2005 GMC Yukon

been to several mechanics and the dealer. only happens when engine is warm, then is misfires, lurches.. like timing maybe off? Spark plugs misfiring? help

Asked by for the 2005 GMC Yukon
Engine overheating, high temperature vapor lock

Recommendations loosen point of the main needle, then appropriate adjustments to be speed and vice needle.