It's not adjustable. Suspect a vacuum leak. While the engine is still cool, spray water on the intake manifold gaskets and vacuum hoses. If you see it get sucked in and the engine speed goes down, you've identified the leak. You can also try pinching the vacuum hoses. If pinching one causes the engine to slow down, follow that hose to the leak.
Tuesday, January 11th, 2011 AT 7:48 AM