'91 100q 5 injectors replaced - now car wont start

[Scruggs Family]

"Agre with everything here.  Thinning of oil from cranking is so impossible!

Oil thins from heat and you have almost none."

Well actually there is another reason.  During long periods of cranking the
temperature sensor gives a 'cold' signal to the ECU which then enriches the
mixture as it is suppose to do.  This rich mixture washes the oil from the
cylinder walls which both flushes the excess gasoline into the crankcase and
tends to reduce the seal between the rings and the cylinder walls resulting
in compromised compression.  I've had this happen to the extent that the
dipstick began to show a milky contamination.  When the engine finally fired
the fuel soon evaporated from the oil and all returned to normal.  

Recall that during early polar expeditions it was common practice to add a
gallon or so of avgas to the radial engine's crankcase to thin the oil so
the engine would crank the next day.  During warm up and magneto run up the
fuel evaporated and the oil regained its normal lubricity.  This is a
practice not needed for turbine engines.

The reason for my engine not firing and causing the washdown that I
experienced... I never found out why.  I eventually disconnected everything
from the battery, let it rest and tried again and everything worked as it
should.  Why?  Ah... these are but weeds in the garden of Audi ownership.

Regards,
Gross Scruggs
Annapolis MD