How to troubleshoot an idle that is going up and down?
How to troubleshoot an idle that is going up and down? Finding the ultimate cause of an uneven idle can be a trial and error process, but a cost-effective way to cure your F-150's idle problems is to start by cleaning specific components to see if this restores a smooth and even idle prior to replacing components. Why does idle speed drop during cold startup? If the idle air control valve did not compensate for these, the idle speed would drop when certain accessories are used. In severe cases, the engine may even stall. The idle air control valve is...