Hyundai Repair: fast idles--than wont start, air intake hose, hyundai sonata gls

Question
I have a 2001 Hyundai Sonata GLS V-6.  My problem is that sometimes it will start to go into a fast idle, revs up and down, than it will not start. If I let it sit for a couple hours than it will usually start up fine and run like a champ.  This will also happen as it is going down the road.  When it does it is hard to slow down by using the brakes.  Please help.  Thank You

Answer
Check for anything loose that may allow extra or unmetered air into the engine.  Especially check the air intake hose to be sure there are no holes or breaks and that it's attached to the throttle body and air flow sensor.

If there is nothing that may cause a vacuum or air leak into the engine, the problem may be with your idle actuator.  The revving up and down is characteristic of the fuel management system not being able to control the idle as desired.  I'd recommend checking to see if there are any stored diagnostic trouble codes prior to replacing the idle actuator or anything else related to the fuel management system.