[V8] cold weather problem ?

[John Dodd]

I've been driving the car at close to -40 with no problems for the past
few days and even laughing at some newer Infinitys ,Subarus etc dead on
the road.
Well ,not a good idea.The Audi gods got me back.No I did not get stuck
but the car is "buckling" sometimes and it feels like I'm towing
something.
At the lights the rpm drops way down (not always).Car starts perfect
,idles nicely to warm up but once I get going it seems to surge. I put
some fuel conditioner in case I have water in the fuel but did not drive
it yet. Any ideas ?
Thanks
John