5K Starting Probs Redux

["McMurray Michael" <McMurray_Michael@macmail1.cig.mot.com>]

Dear Qlisters:
Thanx for the prompt replies and suggestions.  I carefully checked the timing
using the procedure outlined in the Bentley and found it it to be very
slightly off.  I also ohmed out the coil and associated wiring and it all
checks ok.
After adjusting the distributor, cleaning and inspecting the timing and
ignition sensors and basically checking all the stuff I can think of,the car
still has the same problem - no starting spark when hot, but cold it kicks
right off and runs great!.

I suspect a broken wire somewhere (not unheard of in 10 year old Audis) or a
faulty sensor of some sort.  The broken wire will probably need to be found
through inspection, the sensor may have to be found using the shotgun method.

The Bentley has virtually nothing on theory of operation, so I can only guess
what circuits are responsible for providing starting spark when the car is
hot.  Are there any circuits, other than the ignition switch, that will kill
the spark under certain circumstances?  What is the difference between cold
starting and hot starting as far as the ignition system is concerned.  And
what the heck is the "thermal safety switch" for?

As always, your collective wisdom and patience is greatly appreciated.

m.mcmurray
'87 5KCSTQ
'81 BMW R65
'92 F150