Posts Tagged: engine idle surging

Idle Fluctuates Up and Down? Here’s Why

What Causes Idle to Surge? Quick Summary If your idle fluctuates up and down, don’t assume the engine needs major repairs. In my experience, most cases of engine idle surging are caused by problems with airflow, fuel delivery, or engine management sensors. Vacuum leaks, carbon buildup, dirty sensors, and fuel pressure issues all cause the engine computer to continually adjust the air/fuel mixture, resulting in an unstable idle. Fortunately, many of these problems can be diagnosed and repaired with basic tools. Modern engines are designed to maintain a steady idle. … Read More