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First time post, so I apologize in advance for any forum newbie-ness

 

I recently received confirmation from the dealership that the recalled HPFP that was already replaced 25k miles ago has already gone, again. The first one didn't cause any issues...that I'm aware of. It was just removed as part of a recall.

 

I would imagine that under very normal driving (not towing, racing, etc) the pump should last a bit more than 25,000 miles, but it appears not. In any case........

 

I've poked around and performed a few searches and found a bit of info here and there about where it's located, but nothing to do with any instructions on how to replace it. It looks like the pump is located on the back of the 2nd bank of cylinders on the drivers side and attached with a few bolts.

 

It seems (famous last words) like a relatively straightforward job, but I had a few questions that I was hoping someone might be able to answer before I order the part and dig in:

 

Minus the knucle-busting location of the pump at the back of the engine bay, is it as simple as remove the sensor connection, disconnecting both inlet and outlet connections and unbolting\removing the pump? Am I missing something very important?

 

Thanks in advance!

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Thanks Pk! This is EXACTLY what I was looking for.

 

I'd also like to thank bobo83 for sending a quick message as well.

 

I'll order the part up hopefully today, but feel a lot more confident about tackling this one now.

 

Thanks again guys. I super appreciate it.

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  • 1 month later...

So I have a bit of an update after replacing the pump and was wondering if someone might be able to help.

 

I replaced the pump which turned out to be an easier job than I anticipated. The instructions were spot on and helped tremendously.

 

After I replaced the pump and buttoned everything back up again I fired up the car and discovered the same rough start and inconsistent idle. CEL came back on again and was at a loss as to what might still be the issue.

 

Thankfully the Durametric I ordered came in and was able to scan the car. Still getting used to the software, but after quick scan it came back with the following:

 

1025:

Fuel high pressure adaption

Upper limit value exceeded

 

1026:

Fuel high pressure implausible

Value below lower limit value

 

In all honesty, these codes are greek to me. I checked online and here on the forum and it seemed to point back to the HPFP......unless I'm getting incorrect codes.

 

think I installed the pump correctly. Seems almost impossible to do incorrectly unless you forget to put back the clutch and\or stopper. I triple checked everything before I put it on. Was going to head back out to do it all again just to make absolutely sure I got everything.

 

Before I spend any more time I was wondering if anyone else has had this experience or would happen to know if there's anything else I can check for myself or if I should just take it in to the mechanic and have them do a quick once over.

 

Any help or advice would be greatly appreciated.

 

Thanks again.

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Thanks RFM! I'll give this a shot. I've been checking out the tool and the data logging\monitoring and still getting used to it. Do you mean check the pressure value through Durametric (assuming that's even possible), or manually through the shrader valve?

 

I did a search and noticed there are some instructions on how to do a fuel pump test. Loren provided a great drawing on fuel pumps and normal values.

 

I also checked out the 1025 code a bit more online and noticed a few references to the fuel pressure regulator and\or fuel pressure control valve which leads me to believe it could also be a faulty fuel pump (not hpfp). Whenever I see these types of errors I immediately think sensors, but I have no experience with these cars unfortunately.

 

Another thing that crossed my mind is that I happened to get a faulty or defective hpfp. Thinking that's probably somewhat unlikely.

 

We've got a great shop here locally we take our other car too and might just have them take a quick scan instead of guessing until I get used to the durametric.

 

Thanks again for your help!

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  • Moderators

The pumps in the fuel tank are the first link in the chain, check them manualy on pressure and flow rates. If this turns out to be OK, then check the sensors with Durametric if this feature is available, otherwise use PIWIS.

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  • 2 years later...

Chasing this dragon now myself / any updates? Changed the primary (left) pump and filter. Runs way better, but still fails to boost. High pressure steady 40000 mbar at idle and cruise then bogs down to 5000 at ANY throttle over 2000 rpms. Praying it's not hpfp

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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.

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Agreed. The problem started with the primary fuel pump failure which leads me to believe the low pressure pumps failing created stress on the high pressure pump which in turn then failed. Replaced both low pressure pumps, filter and regulator today. (Original and lasted 150k) Runs WAY better but still bogs down when I go for throttle up... Has anyone heard of the cam stopper blowing out/melting being the issue vs the actual hpfp failing? 

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  • 3 months later...
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.

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  • 2 weeks later...
On 10/7/2017 at 2:15 PM, TomBelgium said:

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.

Hello, i have the same problem as you,did you resolved it?

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  • 5 months later...

Hi,

I have the same problems with the HPFP.

All began with 10sec long cranking cold starts and sometimes loss of power when accelerating during highway driving.

Then cold starts became harder and once engine was started it was shaking like misfire. Pushing the throttle to 2000rpm for few seconds was solving the problem.

On a highway run there was knocking and shaking sometimes when accelerating above 3k rpm. Monitoring the fuel rail pressure while driving showed pressure drop to 10bar and after a while returning back to normal 40-100-120bar depending on the throttle position. About 6 months later and 6000km passed HPFP totally gave up with a rail pressure 5bar (fuel supply pumps pressure) reaching 10-15bar sometimes. CEL is on showing P1021, P1023, P1026, P0431. I am using a simple OBD2 bluetooth reader with Android app.

 

Looking for a new HPFP here in Europe I found out that there are two types: 94811031507 - brand new direct purchase and 948110315GX - refurbished, rebuild, reconditioned with exchange option. As I am planning to do it by myself following the DIY instructions on the forums I have some questions.

 

Can you advise where you get your new HPFP from (Europe) and at what price, what part number are they.

Did you remove the intake manifolds in order to replace the HPFP?

Is there any adaptation needed for the new HPFP (software, OBD) or it is working straight away after installation?

Did you disconnect the car battery when doing all this?

 

Thank you 

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