2002 / A6 / 3.0 / Quattro

The car will start for a few seconds (5-7) but then it dies and a second attempt at starting just cranks the engine with no start. On that second attempt the car sounds like it wants to start (coughing like it's trying to start) but it just won't start.

I checked the operation of the fuel pump and there is output when the key is turned on (I checked this by disconnecting the output hose and connecting another hose to the pump output, then into a bottle...I did not check the fuel pump operation during engine cranking)

I have located fuel pressure regulator but don't know what to do next (meaning...is this part a possibility, can I test it, should I disconnect the vacuum hose from it? How do I know if it is faulty?). All vacuum hoses appear to be connected (meaning I don't see any disconnected) except for one which is a clear tube next to the battery. It run vertically, and it is disconnected up top and the bottom runs through the bottom of that trough where the battery sits.

I have no access to any sort of tester, so any input from some of you folks would be greatly appreciated.

Thank you very much for any information...

--maxnpj

 

Pinch off the vacuum line to the regulator and try to start it. If it starts, the regulator is bad. I haven't ever heard of one failing on an Audi though - seems they're a tough part that rarely goes. I'm wondering if your fuel filter is too clogged to let enough fuel through - I'd change that. If it gets too bad it can kill the pump (ask me how I know that).

 

ImTheDevil;

Thanks for the reply. I tried pinching off the vaccum hose to the FPR; but get the same result.

I removed the FPR and turned the car on and holy crap did fuel come out of that port...so it seems that there is fuel flow, although could the fuel filter be part of the problem? I'm guessing it is not part of the problem since fuel came pouring out of the fuel rail once I removed the FPR.

Am I on track?

 

You need to test your fuel pressure, not just volume. A whole lot of volume at 5 psi doesn't do you any good.

But, usually a fuel pump will give different problems (hard to start). Yours sounds more like a sensor issue. Have you hooked up your VAG-COM and watched the readings for reasonableness?

Bob