'87 5KCSTQ reluctant to start cold

[John Larson]

While I've been retired and Audiless for a couple of years, I still have 
a couple of friends with elderly Audis and they rely on me for service 
help.  In this case, it's a problem I never encountered while I was 
wrenching.  Hot start, pretty often; cold start, never. Once the car 
sits and becomes completely cooled off, it takes an extended period of 
time to get it to start (like 1-3 minutes of fiddling).  Giving it even 
the slightest throttle makes it worse. Once it's up and running, no 
problem, and it runs really well.  The cold start valve works, although 
I didn't time it, the control pressure is under 2 BAR in 75+ degree 
weather today.  System pressure is within specs, too.

Before I dive into this, anyone here inclined to give some informed 
commentary?

Thanks for your time.
John.