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Hi all. My name is Mike and this is my first Cayenne. I am new to this forum and I am stoked on how active the Cayenne community is here. I need help from some of Cayenne gurus. The car has an unknown history prior to me owning it. At the moment it will start up after sitting all night and stall after giving it throttle or under load. After it stalls it needs to sit overnight. Here's what we know.
The car starts and stalls when giving throttle or under load.
We can hear the pumps priming when the key is in.
The air filters were very dirty, replaced.
MAF sensors dirty and the wire was missing on both, had to order two new ones, waiting
Coolant was clean
Oil filter was wasted. No metal seen in it.
Oil is not milky at all.
Plugs are clean, not fouled.i think I might smell a little fuel but very faint if at all.
Coil packs look good
Fuel filter changed. The gas that came out of the old filter was really dirty. Drivers side tank looked full, passenger side looked empty. Is that normal?
The car had set for over a year. When we received it the gas was on empty. My friend ran possibly ran it dry at one point.
Steam from oil filler area when cap removed smells like gas. Venting less now.
No smoke from exhaust
The car is getting spark but seems to have a problem with the fuel system. Does anyone know where the port is on the 2008 turbo to check fuel pressure?
Any thoughts would be appreciated. We are checking compression tomorrow and would like to check the fuel pressure.
So a couple things I have READ but not experienced myself.
1. I have heard if you run these trucks dry, it will toast the fuel pump. Google around, there is a way to run only 1 of the 2 pumps pulling fuses. Maybe you hear one priming, but the one that is needed is toast. Pumps are under the rear seats, you have to cut the carpet to get to them.
2. Not sure how much fuel you have but in, but again if you run low, the computer may shut off the fuel system to protect the pump, and you may have to reset it with PIWIS or add a lot of fuel to the system to get the light to go off on the dash, and allow the system to reset. Again just what I have read somewhere in the past, so if that doesnt fix it would suck to have a full tank of fuel if you have to pull the pumps.
3. Get a durametric cable and you can start pulling codes. Faulty MAF sensors can cause this problem too (and you said they are disconnected?)
Curious to hear any info of what happened to the truck?
Thanks for the response. We went through quite a bit today.
Compression check showed all in acceptable limits.
All coils were tested and we were getting spark.
Fuel pumps are operating. The car actually ran ok under load and with throttle for 5 minutes now. Eventually it stumbled and died. It was running very rich. We think we have narrowed it down to the MAF's or fuel pressure regulator. I just need to find out where the fuel rail is to test pressure. Any thoughts for a 2008 turbo?
This says 2003 to 2008 in this doc for the test port, but engines for the V8 changed in 2008 so not sure if this covers it, as the newer cars are DFI, so I would think different system.
Thanks for the response. We went through quite a bit today.
Compression check showed all in acceptable limits.
All coils were tested and we were getting spark.
Fuel pumps are operating. The car actually ran ok under load and with throttle for 5 minutes now. Eventually it stumbled and died. It was running very rich. We think we have narrowed it down to the MAF's or fuel pressure regulator. I just need to find out where the fuel rail is to test pressure. Any thoughts for a 2008 turbo?
Bad fuel pumps are often intermittent before they fail completely. I'm not sure where the test port is on the 957, but I wouldn't rule out the pumps simple because you get good fuel pressure right away. Given everything you've stated, this is where I would put my efforts.
Fuel filter was installed. It made a big difference but still stalling after a 5 minute period. Still a labored start.
MAF's came in and were installed. Fired up immediately. Ran well but after about 5 minutes it stuttered and died when given throttle.
We are looking at vacuum leaks, clogged injectors, fuel pressure and fuel pumps next.
Compression is good and coil packs are operating properly.
05-31-2015, 04:09 AM
Trying to get a 2008 Turbo back on the road
