i have a 2001 dakota truck that it runs good when its cold then when it gets warmed up it will idle high then low then high and low then it shuts off thank u for the help the motor is a 4.7 auto matic they told me it was the computer i replaced it and it didn't help

I would check the TPS on the vehicle. http://www.ebay.com/
Search for your vehicle and engine size.
Auto Zone and Advanced will do free computer scans.