Audi Repair: A4 idles low and stalls on cold days., degree weather, exhaust side

Question
Dear Jan,

I bought a 96 a4 2.8 quattro this summer, and have had no issues until the weather started getting close to zero here in MN.

Symptoms:  on very cold days, it starts fine.  about 10 mins into work, I will get to a stop sign, with the clutch in, and the rPM's drop and it stalls.  Before this happens, I notice that all off a sudden it seems hard to push the accelerator and the car doesn't respond well.

I pulled off on a side street this morning, when it was happening, shut it off to call into work, and then it started up and idled normally the rest of the way.

Again, this only seems to happen with a sudden cold snap, or prolonged zero degree weather.

A plug for cyclinder 5 was replaced last month by precision tune, when I was having the same problem, as that was what the error code came up as for them.

Any thoughts?  Thanks for any suggestions!

Andy  

Answer
It sounds like perhaps the injection unit is freezing.  This explains that if you leave it for a while the unit warms up again and everything stays OK.  Is there a flap you can adjust the intake to draw air in from the exhaust side?  I am not sure if this is done automatically, if so I would suggest testing that first.  Let me know,  Jan