Ok... having trawled through the US Audi forums (I defected to the US around 5 years ago) trying to find a solution to my ongoing issues, I stumbled upon this forum. It seemed like there was a bit more knowledge flying around so figured I might get some better responses here.

Here's a brief history:

Car is a 2006 A4 2.0T with 120,000 miles, no mods
Experienced some power loss under hard acceleration which felt like a fuel cutout
Was getting a P2933 - Fuel Pressure Regulator Valve (N276): Mechanical Malfunction code.
Also getting a B310 code.
The dealer changed the high pressure fuel pump, camshaft and follower under an extended warranty
The B310 went away but the power loss and P2933 came back
The dealer diagnosed the in-tank fuel pump (working too hard)
Changed fuel filiter and the in-tank LP fuel pump
No change to the symptoms.

Below is a VCDS log from before the LP filter and pump change. Below that is a link to a longer log (.xls) after the LP fuel filter and in-tank pump change.You can see the HP pressure drops and corresponding values fro engine speed, LP pressure, throttle angle, LP pump, etc.

To me it looks like the problem is on the HP side, i.e. the LP fuel readings seem fine but the HP readings drop from over 100bar down to single figures. Despite these logs, both the dealership and forum posters keep suggesting the LP side. I can see how a problem with the LP feed would affect the HP feed but if anything, the LP value is at its highest when the HP is failing...!!!

Any suggestions what might be causing these issues?





http://www.legoheads.com/VCDSx1.xls