After having my battery replaced (or jumpstarted or disconnected during a service), my engine refuses to idle and sometimes wants to die at a stoplight. What happened and what can I do?
A- Basically, your idle adaptive memory was erased when your battery died (or was disconnected) and you’re idle air control (IAC) motor is now starting at a nearly closed position. Over time, carbon/oil build up around the throttle plate can restrict the amount of air that can flow past it… as more carbon builds up, the IAC allows more air to bypass the throttle plate to maintain idle (this IAC position is stored in an adaptive memory). Once the battery is disconnected, this adaptive setting is erased, IAC motor is reset, and now you’re engine is chocking for air. To get this back to spec, you’ll need to clean out the carbon/oil build up around the throttle plate to allow your engine to breathe again. To clean the throttle plate and throttle body bore, disconnect your battery to erase any adaptive idle memory that you ECU has attempted to restored. After removing the intake hose from the throttle body, use some throttle body/ carb cleaner spray and spray it onto a shop rag and clean
