TomBelgium

On 7-7-2017 at 6:02 PM, ma77hewsu11ivan said:

No CELs initially. First symptom: random long starts. Second: smell of burnt plastic. Third: more consistent longer starts. Then: total failure at highway speed. Scared the heck out of me. Nursed it home. Diagnosed left fuel pump (primary) bad, swapped it out. Improvement. Then fuel filter. More improvement. Then right pump & FPR. Better still; all the while dreading the ultimate reality that my HPFP was also bad. Finally swapped out a rebuilt Porsche HPFP (thing was actually new) and talked PCNA into helping me out. They sent a $500 voucher. Why? Because I asked nicely. Also my car previously had the service campaign for the HPFP and the unit I pulled off was the newest revision so I'm likely now on at least my 4th HPFP in 158k miles.

 

 

Sent from my iPhone using Tapatalk

 

Did you have a very rough idle at cold starts?

On 7-7-2017 at 4:33 PM, JFP in PA said:

Unfortunately, without codes or other "real time" data capture from the vehicle, this is rather difficult to diagnose remotely.  Is it possible for you to capture data while this is happening?

I took pictures of the engine data before and after starting the car. What data should i upload here?

On 15-3-2017 at 7:36 PM, 09CayennePepper said:

Is that the set point or the actual value? The set point should be 40,0 at idle with the actual below it, dynamic of course. When you increase the throttle the set point goes up as well as the actual, but actual always below set point. If the actual doesn't move up and track the set point then it could be your lp pumps not getting enough fuel to the HP side or I'm afraid it's your HPFP. Outside of the cost of the part there are worse things that can go wrong.

Hi, i have an Cayenne S 2008 model. My high pressure set point value is 40bar at idle and my high pressure actual value is around 4-5 bar at idle. Is this as it should be? My car takes a long time to start after not being used for about a day and when it starts it gives me a very rough idling. This goes away when i revv a little bit or when i put the car in drive or reverse. It gave me a 1026 error a couple of days ago. I deleted it and it didn't came back.

I also forget to mention that when i put the cayenne in Drive or Reverse it also goes to a stable, normal idle.

But as it doesn't give any fault codes i don't know what the problem could be. Also HPFP values seems ok..

Yes i can, I have a piwis tester at home. 

On 2-7-2017 at 6:58 AM, ma77hewsu11ivan said:

Ended up ultimately being my high pressure fuel pump. Decided to replace my entire fuel system + HPFP. Not a bad DIY. Moderately expensive. Tight spaces to work. 

Did you got an Check engine light?

Hi,

Since a few weeks I am the owner of a Cayenne S 957 4.8 from 2008. But I notice that the car struggles to start after standing a few hours.
When I try to start it in the morning it takes a few seconds to start and then it idles quit rough. It seems to misfire in some cylinders. When I press the accelerator to 2000rpm for a second or 2 it goes to a "normal" idle and the shaking and rough idle are gone. No error codes are shown on the dash or Piwis tester.
There is no unusual noise coming from the engine and it had a new battery last week (unfortunatly that didn't fixed the issue).

Anybody who had the same problem before and has any ideas how to fix it? It drives great it is just the rough idle at cold start that is not right.

Kind regards

Tom

Hello, 

I recently bought my first Porsche, a Cayenne S from 2008. When I bought it I thought the engine was running fine, started OK, no bad ticking noise or whatsoever.
But maybe I am to obsessive but now I am not 100% sure my engine is making the right sound. So I tried to find videos about a normal good running 4.8 engine but seems like all of them on youtube have some kind of problems. Is there anybody with a good running engine who wants to make a video and put it online? It can also be used then as a reference for other buyers who have no experience in Porsche engines.

Kind regards

On 2017-3-18 at 10:48 AM, ma77hewsu11ivan said:

I know this is VERY old but I'm dealing with the same issues. Ever resolve this?

Hello, I have also the 1023 error and hard to start problem. How did you resolve it?