There isn't an idle by pass, and that wouldn't be the problem. Idle speed is electronically controlled. It could be ignition or fuel related but impossible to say without doing some basic tests or being able to experience the problem first hand. There is a company that independent auto repair shops buy their information from that the same information inexpensively to do it yourselfers. The information is year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online
Information found on Alldata may help you get to the source of the problem.