Audi a3 TDI, funny start.

[emery1990]

My mates audi a3 140 tdi doesn't start sometimes, he notices that if not used for a day that in the morning it doesn't start. It's been to the garage twice and £500 spent and it still does it. He gets it to start using easy start but said he had to have the accelerator fully down. So it is a fuelling issue, I was thinking maybe a tiny fuel leak then pressure dropping, but I've told him about priming it a few times before starting, yet it still didnt start without easy start. Anything obvious?

[Seanl]

Can you/he hear the fuel pump running when turning the key without starting it? Fuel pump or fuel pressure regulator IMO. Or just a blocked fuel filter.

[emery1990]

hello mate, yer he said he can hear it priming up. It only does it when he's not using the car. I've been told maybe wiring, but that'd be more random. It has had a lot of money spent on it, so surely they would of tested those things, but maybe not! I did say to him first the fuel pump, but garage said it's ok.

Is there a way of testing the fuel pump regulator, resistance test or anything?

[Wayne]

Non return valve on the fuel pump maybe