I have a 2003 Audi A6 Quattro (3.0) and it has problems starting. It starts from cold just fine and runs perfectly but when the engine is warm and the car is turned off and started within 40 minutes it will refuse to start until it has time to cool down. During the summer it had problems starting much more frequently (every time), but it has been mostly ok this winter. It failed inspection (but got a waiver) because of rich exhaust, which I would think means that it needs new O2 sensors, which would possibly address starting problems. Is there anything else it could be? I have only a max of 500 to fix it otherwise I have to sell it as I am a student. When it has problems starting it will always crank and sometimes if it catches and start it will lurch pretty violently and revs will stutter and sometimes it will die and sometimes it wont. Any thoughts?

 

I will put money that your O2 sensors are fine as they wont cause the rich fault or drive ability your are describing. I think it is much more likely you have a sticking injector when the car is hot and causing your engine shaking, fuel trim faults, and all of it. The only other thing that comes to mind for are a vacuum leak (usually causes a lean fault though) or a clogged suction pump (will cause fuel trim faults but not typical for drive ability issues). If you can get actual DTC descriptions I might be able to give you a better answer. If its a fuel injector you might meet the 500 dollar limit, if its either of the other two things I described you should be between 100-200 dollars.

 

To be clear there aren't any problems when the car is driving. The lurching is immediately after the car starts and goes away after about a minute. I wait normally just wait it out in park and don't put it in drive until it stabilizes at like 800 rpm.

 

Check the recall on this car, I believe it is the fuel pump and they will replace it. it has a danger.