Dennis C

In the past, my Cayenne S always primed the fuel pump when the driver's door was opened. This operation was audible, especially in the garage. I've noticed recently that this no longer takes place. The car starts, runs and drives just like it always did.

Any thoughts? Is one of my pumps going bad or is there potentially another problem?

Thanks,

Dennis

deilenberger

I don't believe it does it every time.. it does it after some period of time has passed after the last shutdown. The idea is to repressurize the fuel rail after it bled down pressure from sitting. Since that bleed down takes some time - it isn't necessary to do it every time the door is opened.

Aperture776

I was wondering the same thing. Thanks for the information.

Dennis C

It seems like it used to always do it. Now it never seems to do it...

bigbuzuki

If it seems that it is never doing it, it could be the left pump has failed.

For starters troubleshoot by pulling the fuse for the right pump in the engine bay fuse box and see if the car still runs with just the left pump powered.