A6 C6 2.7TDI Fueling problem

Hi everyone,

After standing for a couple of weeks the car will not start. It turns over normally, no trouble codes are present so trying to trouble shoot the fueling.

Tracked down the fuel pump relay to the left hand plenum electrical box ( relay part no: 8Z0 951 253 )

If I bridge pins 30 and 87 (thick red and green ) the fuel pump runs, pumping around half a litre in a few seconds at the fuel filter.

The thin red/blue has 12v on it when the ignition is on, from what I red the ECU should apply a ground for a few seconds to the red/white wire.

Checking the relay unplugged with 12v across the 2 thin wires ( pins 85 and 86 ) the relay works, connecting the green and red ( pins 30 & 87 ) .

I guess this points to the ECU not suppling the earth when it should .. my question is do u think it is safe to apply an earth to red/white to test this theory?

I did try cranking the motor with the fuel pump running ( pins 30 & 87 bridged ) but the motor didn't fire so perhaps there are further problems?

Any thoughts or suggestions warmly received...

Cheers

John