Hi guys. Common problem, real simple solution. You caused the low idle by disconnecting the battery. The Engine Computer lost its mind and has to relearn "minimum throttle". With some vehicles like Volkswagens, that means towing it to the dealer for a very expensive repair bill. For Chrysler products, drive it at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedal. When the Engine Computer sees high manifold vacuum for at least seven seconds, it knows you're moving and your foot is off the gas pedal. That's when it memorizes the voltage from the throttle position sensor. From then on, any time it sees that same voltage, it knows it has to be in control of idle speed. Until that relearn takes place, the idle speed will be too low unless you keep your foot on the gas pedal, and you usually will not get the nice idle flare-up to 1500 rpm when you start the engine.
What happened to make it stay running is you coasted for at least seven seconds during your last drive cycle.
Sunday, July 3rd, 2011 AT 7:46 AM