certainly sounds like fuel m8, although I had to listen really hard to hear if pump was working, since it's quiet anyway and only runs v briefly during key operation since fuel lines to metering head should normally be under pressure anyway and don't need much push from pump to initially start up. getting fuel to the metering unit would probly be your best best to start with. I had corroded fuel line under heat shield at front of car, stopping lines from pressurising & hence limited fuel to metering head. if it's been laid up for a year, probly all fuel evaporated & any fuel in the tank poss badly degraded now too - apparently does happen & needs new fuel instead of what's in the tank already. also, have you checked that the cold start valve/injector is working ? there is a procedure for doing this in a haynes manual (no, course there's not a manual for quattros, that would make it too easy) - valve should run, if I remember correctly (?) for about 1 to 8 seconds when key is turned - this is effectively the cold start 'choke' for the FI, like the choke/enrichment you'd get on a carb. Problem is, for me anyway, that the duration of the cold start valve fuel spray depends on your engine identifying how cold it is outside, in order to tell the cold start valve how long to run for - this info on temps taken from another 2 engine sensors, but dunno which one and I can't afford to change either, so just takes longer to fire up. I found that changing the plugs made a big difference, so car is easily usable, but didn't solve the problem entirely. you could probly unbolt the cold start valve, put it in a jar & see if any fuel coming out on key operation. as you reckon, tho, I'd check any fuel tank breather isn't blocked (take fuel cap off to be sure), then wire fuel pump direct to batt to hear if working first, then reconnect and see if any fuel getting to metering head & then look at cold start valve if still a problem
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