[s-cars] Engine surging

[Bob Frizzell]

S-men,
Now that we've hit the deep freeze in Edmonton (-20C) my wife and my S4 are starting to act up.  Maybe you have some ideas about how to deal with the latter.  After about 10 minutes in the cold the car starts to surge, going from approx 800 rpm to 2000 rpm, and occasionally slows down and stalls.  Seems like a freeze-up in the fuel source somewhere.  I've tried gasoline antifreeze with no change.  Any BTDT, ideas?
Always appreciative,
Happy New Year to all you great guys.
Bob, damn cold in Edmonton
93 //S4