What would cause a 1999 jeep grand Cherokee 4.0L to load up on fuel while idling only?

A 1999 Jeep Grand Cherokee 4.0L could load up on fuel while idling due to several factors, such as a malfunctioning fuel injector that is leaking or stuck open, causing excess fuel to enter the engine. Additionally, a faulty idle air control valve could disrupt the air-fuel mixture, leading to rich conditions. Other potential causes include a clogged air filter, a malfunctioning mass airflow sensor, or issues with the engine’s sensors that regulate fuel delivery. These problems can result in poor combustion and excessive unburned fuel during idle.