I purchased an Audi A3 TDI 2006 (BKD engine) around 4 months ago and it developed a fault whereby if the fuel level was below half a tank it would not start. This only happens when the car has been left overnight. It cranks fine but it seems itâs not getting any fuel. It can be started with easy start or when the fuel level is raised again to above half a tank. I took it to the Audi dealer and they first diagnosed fuel contamination (oil leaking in fuel perhaps?). Tank was emptied, new fuel filter and fuel lines cleared. Got the car back and same thing happened. Again I took it to the dealer and they then replaced the in tank fuel pump. Again the same problem occurred with the same symptoms. There are no fault codes or anything and I believe the dealer hasnât got a clue whatâs wrong. Any ideas what it could be? I think itâs definitely a fuel issue but what to try next? Could it be a tandem pump issue? I have read these are prone to failures. I have already spent over Â£900 on this and still no fix so I want to make sure the next thing I do does fix the issue. Thanks for your help.