Lurching start 2004 Audi A6

fuel pump , now they are putting alchohol in petrol it screwes up the pump

Does it have normal fuel pressure and has the filter been replaced ?

Iac tps or egr could be bad . find the specs and test them with a ohm meter.

It could be a fuel issue add some heat in the tank water can be picked up easily when refueling could also be an injector issue

Lurching? You mean kind of jerking when accelerating? Another person had a similar problem. To not be repetitive, this great diagnostic article points out to six possible causes of this problem:

http://yourhandymanzone.com/Your_Handyman_Zone_How_To_Pages_Vehicle_Car_Zone_Cars_Trucks_Vans_Transmission_System_Jerking_When_Engine_Accelerated_Transmission_First_Gear.htm

You could have any of these problems:
1) vacuum leak- broken air hose or disconnected air hose.
2) water in the gasoline- add a water remover to you gas tank.
3) bad or disconnected spark plug wire(s).
If this were my Forester, I'd take it to a mechanic who has a electronic engine tester..

On a lot of vehicles there is a transmission speed sensor that receives data that tells it how fast the car is going and shifts accordingly. If this sensor is bad the transmission can't function properly. I would have this checked, they are not that terribly expensive, and not that hard to change on most vehicles. Hope this helps.

try the camshaft position sensor code 341! mine had a lurching problem it would redline at only 3500 rpm instead of 5500rpm in all gears even neurtral.

If You have 3.1 v6 engine check the crank shaft position sensor. on other engines you may have problem with harmonic balancer.

This could the problem with on board computer please get it checked..............