For the last couple of weeks we have had freezing weather, and my S has been acting a bit strangely. It usually fires right up in the morning, but after sitting at 2k for about 2 or 3 seconds, it will just crash. If i give the throttle a little bump when the rpm's start to tank, then it's fine and continues to warm up normally. Any suggestions?

 

Check the throttle body and clean the TB and MAP sensor hole if necessary.