Since the issue stems around the idle, the first thing I would recommend checking is the idle air control valve (IAC). It is on the throttle body. When you remove it, it will have a pintil at the end of it that allows air into the engine to maintain idle when the throttle plate closes. When the problem starts, disconnect it to see if there is a change. If no change, remove it and make sure it is clean. Have a helper turn the key from off to on to see if the pintil moves in and out. If that is good, you may have an issue with the charging system. Check the fuseable link between the battery and alt. If it is bad, the alt can't properly charge. Consequently, you end up with electrical issues that can cause this and eventually kill the battery. In addition to cleaning the battery terminals, make sure the ground to the engine block (from the battery) is clean and tight.
Wednesday, January 12th, 2011 AT 8:57 PM