Throttle body may need to be cleaned and adjusted.
December, 16, 2012 AT 9:48 PM
Because there isn't much load on the engine in neutral. How long since a tune-up? Clean the throttle-body and idle air system.
December, 16, 2012 AT 9:50 PM
Although there are several things that could cause this I would suspect an idle air control valve issue. Get a manual on the vehicle and locate the iac valve and tap on it with the car running and see if it stalls. Use an assistant in the car to keep it running if you need to.