I had mine do that before the fuel pump chucked it - apparently they need programmed properly. The pump will cut out if the ECU thinks the fuel tank is empty. It needs reset with a 1/4 tank of fuel in it

I can't find it listed under Silent Witness but given that there are 2 A8s together I wonder if Audi loaned out cars for this?

http://www.imcdb.org/vehicle_5749-Au...p-4D-1999.html

If the pump isn't installed properly and runs dry then it can draw too much current for too long and burn out the fuse.

This is my gut feeling. The only thing that made me doubt it was this garage have spent weeks and thousands trying to diagnose the fault and failed. I reckon the initial problem was the ignition switch, and now they've messed about with the fuel pump, I need to sort that too, where it was only the switch/wiring to begin with. Let's see. Thanks, Psyche.

Richy - Good effort, but that's a facelift.

Thanks, Dave. Will look in to what I need to do to calibrate via VAG COM, top stuff. +++

Depends on the kind of garage that did the work to date - if a main dealer they probably went for the 'well that doesn't work as intended so we'll change it for a new one and see if it fixes it' rather than following a logical fault finding exercise that'd probably cost more in labour than they could justify charging.

Potentially a day with a decent specialist would sort it if they can work through from first principles. To confirm the switch is duff you need to know which pin on the back should be doing what and at what time in the starting/running cycle

If it's run and then cut out at least the switch was working then, even if intermittently. That pump assy is a mare to get seated properly, even whan it looks to be right. Worth undoing the fuel rail and switch it on see if it blows fuel everywhere, should be able to get a pressure reading up there too.

Is the pump fuse shared buy something else too if i remember rightly? If not the pump drawing too much juice could be the something else maybe?

Welcome back Amar +++

(Not as if I'm a regular anymore myself but still like to pop in from time to time to see what's going on :) )