vtraudt

Lets assume for know you have no fuel.
You don't need to 'crank' to see power to the fuel pump. Ignition on will 'prime' the pump for a few seconds.
Check if you see battery voltage (i.e. over 12V) at the pump.
If that is reliably the case, check Ohm of the pump motor itself.
Not sure what the readings should be (does Bentley say anything?), but 'infinite' (=open circuit) or 'short' (0 or very few Ohm) would clearly point towards bad fuel pump motor.

Another check would be to put 12V directly to the pump. It you don't hear it running, change it out.

CaptinGonads

I have the same problem on my 2.8 quattro, today went to start my car. Didn't hear a pump humming, doesn't seem to be pressure. I just replaced the pump and still does not start. Where is the relay for the fuel pump? Checked the fuses in the dash on the drivers side. Are there more fuses than those?

vtraudt

To check if the pump itself is working, I would take the fuel pump relay out and manual jump it. Pump should then be running.
Since you are troubleshooting the fuel system, go to Autozone and get the fuel pressure gauge kit and hook it up. Not sure if Audi has a Schrader valve; I remember having problems with the 1.8T AEB in this respect).

In the power loop to the fuel pump, there should also be a 'crash/impact' circuit breaker (aside from fuse and relay). Forgot where this is on the Audi. They normally can be re-set by pushing a button.

I can look up the specifics (but likely others can fill in the blanks right of the bat), but specify year/model/engine code.

cvbadass

You can rent a fuel pressure tester for free at Autozone. If the car will never start, and you have fuel pressure, it could be the ECU relay.

turbo510

The fuel pump relay is under the dash, reached by removing the knee bolster panel. The fuel pump fuse is located in the main fuse block. However, don't just guess that you need a fuel pump, then guess that you need a relay, or guess that you need a fuse. You can use VAG-COM to switch on the fuel pump without the car running, which allows you to troubleshoot the fuel electrical system methodically.

CaptinGonads

I've created a new thread because I have a feeling this is more than a simple fix. BTW the pump and relay were fine, bought a pump for nothing.

CaptinGonads

https://www.audiworld.com/forums/sho...8#post24155928

Myboys1stcar

I know this is an old thread, but I hope it will help someone.
2000 Audi A4 B5 1.8t Quattro
My car's symptoms:
intermittent stalling while driving any speed with no warning. While driving complete power loss and EPC light on. Wait 10 minutes to a couple hours and it would restart no problem and run like new. Occassionally no throttle response until 2nd restart.
replaced: fuel pump, fuel filter (PIA on quattro), Maf sensor, crank sensor, coolant temp sensor, cam sensor. Reset ecu. Still nothing. Did all this based on some really good and well thought out forum threads. Really appreciated this as we narrowed down possibilities. I live in Fl and started to notice a pattern after rain or heavy moisture combined with hot days. As it got closer to summer and hotter the problem got worse until a tow was in order. Pulled the wiper cowl off and it was FILLED with water. Punched out the rubber grommet and drained. Pulled ecu cover off and thankfully it was dry. I figured the must have still been moisture in the relays contained in the ecu housing even though they looked dry. I pulled the Ecu relay out and took it apart. Dry. But noticed the braided copper wire was very close to the other poles on the relay. Replaced relay and problem solved. The heat and moisture combination in the housing was enough for that wire to expand just enough to short out on the other poles shutting down the ECU.
Now I have all known problematic sensors replaced and the car is running like a champ. I hope this helps someone with a tough diagnosis and saves you some money.
cheers!

clancy

Myboys1stcar

Yes. Sure was. My 17yo actually pulled the relay apart and confirmed that temp change was just enough to cause the change and short. Sharp kid.