Need help troubleshooting

[SDS]

My wife's '06 A4 2.0T, 200k+ miles......car died on her this morning, and her description of the event sounds like it ran out of fuel. Car gradually lost power until it stopped. Electrics seem o.k., and car will crank and idle for 5-10 seconds after it sits for 20 or so minutes, but stumbles and dies. Gauge says it has a 1/4 tank. The first thing I'm planning to do is add 4-5 gallons of fuel just to be sure, but I'm not confident that's the issue. Cam shaft and LPFP were replaced at 118k miles, I replaced all 4 coil packs a month ago (car stuttered under load and was throwing mis-fire codes on all 4 cyl.'s) and it has ran fine ever since. It currently shows a P2181 and P0442 code.....I have the coolant temp. sensor and a new N80 valve, but haven't replaced them yet. I don't think that would cause the current problem anyway.
Any advice? I'm hoping it's just water in the gas, or maybe the fuel gauge sending unit is bad and the tank is actually empty. Is there a fuel filter on these cars? HPFP bad? MAF sensor bad? Anything you guys can think of to check would be greatly appreciated.

[Deckster]

I actually had something similar happen in my car, and I'm pretty sure I replaced the fuel filter and n80. I don't fully remember since this was over 3 years ago. :(

Now that I think of it, I definitely replaced the fuel filter that time. The fuel filter is located where your gas tank is. On the rear passenger side.


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[atvhead]

fuel filter....pretty easy job

[SDS]

Thanks guys.....got a fuel filter coming this afternoon. Looks like I can swap that out in the library parking lot where the car is now, and not have to get it towed.

[SDS]

So I swapped out the fuel filter, but the problem remains. If I purge the valve on the HPFP, fuel sprays out, so I have fuel, and if the car sits for 20 or so minutes, it will start and idle for a minute or two before it dies. Is the HPFP bad? Is there enough vacuum in the pump when it's not running to pull in enough fuel if it sits long enough to allow it to start and idle for a short time? Is there a pressure regulator somewhere? I'm under the impression there's just a LPFP at the tank, and a HPFP prior to the rail and injectors. I can hear it all cycle when I open the drivers side door, and I can hear the LPFP cycle when I turn the key to aux., so what else if not the HPFP? The two connectors are seated and good, fuse is good......is there a controller for it somewhere?