My son's 2000 A4 2.8 was running fine, then just stopped running. It is not out of gas. It will start, but run just briefly, but at very low RPM and won't accept any throttle increase (i.e., you can try to give it gas, but it will not increase the RPMs and basically kills the engine). It acts as if it could be a fuel pump issue, or throttle position sensor perhaps (if the Audi even uses a TPS???).

When we go back to the car, I understand if I pull the rear seat, I should be able to hear if the fuel pump is running...correct? If it is, then what to check?

What about fuel relay or relay fuse? How can I troubleshoot those items? Which is the fuel relay fuse (how do I identify the correct fuse...and then, how do I know if the fuse is good or not?).

If I can verify the fuse and the fuel pump seems to be running, then what? I'm trying to help as best as I can mechanic-wise, so any help is VERY appreciated.