It sounds like you either have an engine vacuum leak or the idle air control valve (IAC) is bad. The IAC is responsible for maintaining the engine idle speed. First, check for vacuum leak issues. If none are found, then suspect the IAC.
If the check engine light is on, have the computer scanned to identify trouble codes. Most parts stores will do it for free. That will help identify where the problem is coming from.
Thursday, January 16th, 2014 AT 5:27 AM