I am knew to audis, this 99 A6 being my first. after owning it a few days, it decided to NOT start after being run and sitting a few minutes.
So I say to myself "maybe I should invest in some diognstic equipment" so as to figure this problem out.
Well I did, I purchased the VAG_COM affair from ROSS and it shows NO engine codes!
This has happened to me several ( about 4 ) and it is becoming more frequent.
What happens is, after the car is warmed up and driven, it does not want to start after being shut off for a few minutes.
It just cranks over with no inclination to start. After 4 or 5 trys the battery goes low and it cranks slower and slower ( i am certain I need a new battery) After getting a jump it still does nothing but crankover.
One time upon getting a jump, and still no start, I tried it again ( without a jump ) and it cranked over slowly but sounded like it wanted to run so I feathered the gas pedal and it started!!
Thought maybe I had vapor lock but the last time this happened was at the gas station where I had just filled up. Had nothing to loose so I put the gass pedal to the floor and it started upwith black smoke.
If any one has had this problem or has any ideas about this your input is appreciated
THE BIGGEST CLUE I HAVE IS THAT THERE ARE NO CODES
PLEASSE HELP ME BEFOREI DAMAGE MYSELF AND OR THIS car
THANKS beng

 

Safe bet its the coolant temp sensor, they don't always throw fault codes and cause what your experiencing.

 

I did have that code originally, ( it implyed that it was intermittent ) and cleared it because I had cleaned the emissions pump and in the process I disconnected some connections and neglected to hook one up, I hooked it back up after runing the car. I though maybe this was the one giveing me the temp code. So far this makes sense THANK YOU