Motor turns, battery is fine. Engine does not ignite. Spark happens but the engine does not hold. AFter 5 mins car starts. Once its warm no problem starting. Cold start is the issue. what do you think is issue? fuel injection, fuel pump???. I have seen the car stall on second gear sometimes on high throttle, reduce throttle it will come back on. I am suspecting some issue with fuel injection???
mechanic tells me three things going wrong 1. temp sensor for fuel to be fed properly based on engine temp is not working 2. engine speed sensor that measures fuel based on speed is not working 3. PCV suction pump is not working. He tells me 1 and 2 is related to starting, problem 3 is not related to starting but it is related to performance and mileage.
I’ve seen your number 1 on other cars(Acura and Subaru) that will eventually start because the ECM goes into limp mode. The temperature sensor is usually suspect because, when it measures the wrong thing, the air fuel mixture is bad.
Not sure how expensive and difficult they are to replace on an Audi, tho.
Just for others information. temp sensor plus speed sensor worked out to 117 +204. PCV suction pump is another 200.