B7 No fuel pump priming noise when key is in. Cranks but won't start

[jayden.world]

Hi all.

I have a S4 but I assume this issue is universal across B6 & B7 platforms.

Audi is giving me another headache.

The car has been sitting for 1 year and 1 month now.

I was hearing some robotic/machinery like high mid-high to high pitched humming noise from rear areas
and I thought maybe it was normal but then apparently it was most likely a fuel filter issue according to my research.

I've been turning on the car regularly like every 1-2 weeks during the COVID and the car had no problem turning on.

However, when I tried to turn on the car yesterday, it cranked strongly no problem but won't start at all.

One thing I noticed was, I did not hear any kind of that whirring/low bass humming noise from the rear, which I assume is the fuel pump priming noise.



So according to my research, it seems like this is very likely to be the fuel pump which I hope is not due to the price of the fuel pump but

do you think changing the fuel filter and the fuel pump relay "614" behind the driver's side fuse box inside the car, not by the ECU box in the engine bay, would do the magic and revive the fuel pump?
Or do you think the fuel pump is RIP due to me ignoring that high-pitched humming noise?

I also read someone saying that if the gas tank is at 1/4, maybe filling up the gas would do the magic but even at 1/4, I should hear the priming noise, no?

Please let me know.

Thank you.

[bwdysart]

Hi all.

I have a S4 but I assume this issue is universal across B6 & B7 platforms.

Audi is giving me another headache.

The car has been sitting for 1 year and 1 month now.

I was hearing some robotic/machinery like high mid-high to high pitched humming noise from rear areas
and I thought maybe it was normal but then apparently it was most likely a fuel filter issue according to my research.

I've been turning on the car regularly like every 1-2 weeks during the COVID and the car had no problem turning on.

However, when I tried to turn on the car yesterday, it cranked strongly no problem but won't start at all.

One thing I noticed was, I did not hear any kind of that whirring/low bass humming noise from the rear, which I assume is the fuel pump priming noise.



So according to my research, it seems like this is very likely to be the fuel pump which I hope is not due to the price of the fuel pump but

do you think changing the fuel filter and the fuel pump relay "614" behind the driver's side fuse box inside the car, not by the ECU box in the engine bay, would do the magic and revive the fuel pump?
Or do you think the fuel pump is RIP due to me ignoring that high-pitched humming noise?

I also read someone saying that if the gas tank is at 1/4, maybe filling up the gas would do the magic but even at 1/4, I should hear the priming noise, no?

Please let me know.

Thank you.

I can’t comment because the S4 might be different, but what I will say is if you end up replacing the fuel pump yourself you may regret having a full tank. It’s easier to not spill gas with a low tank


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[Theiceman]

Plus it doesn't prime when the key is in, it primes when the door is opened when engine is cold and pressure is below spec..
Somone might correct me but I don't think it does it if it feels fuel pressure is up to spec.

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[Charles.waite]

Plus it doesn't prime when the key is in, it primes when the door is opened when engine is cold and pressure is below spec..
Somone might correct me but I don't think it does it if it feels fuel pressure is up to spec.

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It does both. And the S4 uses the same port injection system as the B6 S4 and the 1.8t/3.0. So its operating pressure is like 6bar or something.

OP its possible your fuel pump is locked up or the fuel pump relay went bad. I'd check the relay first since its a cheap thing to replace. Hell maybe just get a new one and replace it and see what happens. if the relay is stuck or failed then the pump wont run.

[Theiceman]

Mine doesnt ... isnt that odd....

[Charles.waite]

My 2008s pump primes on door open and key on (I think). My old 2006 didn't prime on door open though. Either way I think Audi messed with the priming behavior of the course of the b7 production.

[esandes]

There's also a specific fuse, 28, for priming the pump. It may be bad. Hopefully it's just that.

[oVeRdOsE]

There's also a specific fuse, 28, for priming the pump. It may be bad. Hopefully it's just that.

+1,

also make sure its in the good spot. Had a non-working pump , and all my fuse were OK, before realizing that after a dashcam install I put some fuse in the wrong spot. On my B7 , empty spot is next to the fuel pump fuse holder.

[sastanley]

Bringing back an old thread...I have the same issue. B7 - Intermittently, the pump will not prime (and of course car won't start.) Same behavior..no pump whirring when door opened or key turned to "ON". My issue is, my car has NO RELAY in position #1. There is no wiring in that socket. My Bentley manual says it should be there right next to the big 640 Servotronic relay. Where else would the relay be? Not under the ECU either..I checked. :)