CayenneS-Re

Cayenne S 2004

I was really upset and took it out of my car by driving a bit aggressively with a lot of stops and heavy accelerations. 10 minutes in and the car started to stall. I thought that it may be a clog so I let it rest a bit and tried to drive it off. It kept stalling after a few seconds. Would start fine and then begin to stall after a few feet of driving. Gas level was just below the quarter tank mile (low gas indicator had just come on) so I did not think the gas could be the issue but decided to get it filled anyway. Barely made it to the station and after filling the tank, guess that, the car WORKED FINE!

But after three days of regular driving, the gas was again just below a quarter tank today and the engine started to stall again. Again, I filled it up and the issue got resolved. Can anyone guess what the issue is here? A sensor, fuel indicator, fuel pump issue? Any help is appreciated...

Divot

Do you have any error codes from a scan tool? Your local auto parts store will usually let you hook up their OBD if you don't own one, or have access to a durametric or PIWIS. If you are stalling, it should throw an error code.

Maybe someone else had the same problem, so your aren't just changing parts by process of elimination.

kmagnuss

If filling your gas tank cleared the issue twice I'd say you have one of a few problems...

-Your gauge isn't reading correctly due to a faulty sensor. To rule this issue out next time it happens just open the gas tank and you might hear a vacuum hiss... then your CS 'might' start to work again... this leads me to suspect #2..

-Gas tank vent valve isn't venting... it's clogged.

There could very well be other issues of course but I'd look at these two first.

Divot

I always hear a vacuum hiss when I open the gas cap.

The 996 has a known failure of the EVAP vent system valve, but haven't heard about it on a P!g. It's a PITA to switch out, just to find it isn't the problem.

My 996 got fixed when I went from some chain auto-parts-box-store aftermarket gas cap, to OEM.

Dennis C

My guess would be impending failure of your primary fuel pump. It's a common issue for first generation Cayennes.

CayenneS-Re

Thanks Dennis. I will try the next time it happens to see if it is related to the gas tank vent valve.

CayenneS-Re

Sorry I meant Kmagnuss about the vent valve.

Dennis, what makes you think it is related to the fuel pump? Wouldn't the stalling continue if the fuel pump was not working properly even after filling the tank?

CayenneS-Re

Divot, I will have it scanned tomorrow and will post it here.

garrett376

Your exact issues have been discussed here on this forum when one of the two fuel pumps is dead.

endless_corners

Sounds like a fuel pump is on the fritz. Time to pull some relays.

XR4Tim

Another thing to check, which I've seen happen on an Audi with a similar fuel pump setup, is one of the fuel pump venturi tubes (which sucks fuel from one side of the tank to the pump on the opposite side) had been disconnected. Below a certain level fuel level, it would suck in air, and stall.

Dennis C

When my primary fuel pump failed, the initial symptoms included inconsistent fuel pressure and sporadic stalling/sputtering. Sometimes the vehicle ran fine, sometimes it stalled. My dealer ran some diagnostics on the vehicle and determined that the fuel pump couldn't maintain adequate fuel pressure on a consistent basis. Replacing it did the trick!