Why would my Linclon Mark III engine stumble at idle?

Your Lincoln Mark III engine may stumble at idle due to several potential issues, such as a vacuum leak, which disrupts the air-fuel mixture, or a dirty or failing idle air control valve that manages engine airflow at low speeds. Additionally, a clogged fuel filter or failing fuel pump can reduce fuel delivery, causing unstable idle. It could also be related to issues with the ignition system, such as worn spark plugs or faulty ignition coils. Conducting a thorough diagnostic check can help pinpoint the exact cause.