89 200Q- No start problem in mild weather

[gschulte@cinergy.com]

Listers: 
I am in desperate need of help from your expertise.
I purchased my early (VIN 1790) 89 200Q 8 months ago ( third Audi)- Great
condition & great price- and thoroughly love the car- When it runs.

However, it has a very annoying habit of not starting when the ambient
temperature is in the range of 45-65 degrees F. Typical scenario- Car runs
great- Park it for several hours when outside temp is in that range- it will
crank continuously with no hint of firing. I have tried off & on  for up to
an hour (great battery) with same results- If I then leave it sit for
another hour or so, and then try, it fires right up and runs great again.
There is no sputtering or missing to indicate a typical fuel pump or filter
problem.

Car has always cranked for 5-8 seconds on cold start before firing- Local
dealer (Northland in Cincinnati) says that is normal for this model. Only
exception is when ambient temp is below 20 degrees F- Engine fires
immediately.

Have been to dealer twice with limited success- First time replaced hose
(intake?) to correct idle stalling problem. Second time towed in- Kept it
for a week- Started perfectly and ran great every time they ran it- They
checked it over "completely" and found nothing-but temp was below 45 degrees
F entire time they had it. I suggested to service manager that he check cold
start valve/sytem- he said it would not cause the problem. 

I have addressed ECU ground/ Intake manifold possibility by running a jumper
to firewall ground point. Have replaced plugs & fuel filter; Distributor cap
& rotor look good. I have run fault code and output tests both when running
good, and when in no-start condition- Everything checks OK.

My wife says dump the car- HELP!!

Also- Can anyone recommend a good mechanic in Cincinnati area?

TIA
Gary  Schulte