- gummed up or stuck open idle air control (IAC) valve or IAC motor - carbon buildup on the throttle body - idle adaptation needs to be performed after replacing or disconnecting the battery - faulty electronic throttle body or IAC valve (motor) ...
An example of an Idle Air Control (IAC) valve: The IAC is seldom completely open or closed but remains constantly in motion; controlled by the PCM. The PCM uses input signals from the oxygen sensors, the throttle position sensor, and various other sensors to determine how much air should b...
A damaged or stuck-open PCV valve will allow too much air to go into the intake manifold, resulting in a faulty fuel-air mixture idling and a build-up of pressure in the crankcase, creating various types of oil leaks. And this, in turn, can lead to a host of other problems, includin...