Fuel issues when parked nose up

Similar problems here - http://www.audi-sport.net/vb/a3-s3-...-tdi-170-08-sudden-poor-starting-morning.html

I had this problem (in fact mine wouldn't start if parked nose up overnight) and its just been fixed (see the other thread).

The fault was the lift pump. It was letting fuel drain back to the tank so the engine was starved of fuel. Crank enough and it would splutter into life.

The garage had a devil of a job finding the fault. Nothing was recorded in the ECU, they had to diagnose it the old fashioned way. It was trial and error that I found parking it nose up made the problem far worse so they were able to leave it on a ramp at the garage.

Once the pump had been replaced they left it nose up overnight and it started straight away. It also now starts more quickly and smoothly. I'm yet to leave it parked up for a few days as a final test but so far so good!

The garage think that the pump may have some kind of no return valve in it that might have failed. It terms of pumping fuel it tested fine, but it was just letting fuel slowly drain away when parked up.

Any slight air leak on the suction side of the fuel system can cause this. Often a sod to find as they rarely leak fuel!
Peugeots used to be prone to it.