09CayennePepper

Like Lewis said it can be any number of factors, there are 5 to start with, 2 in-tank fuel pumps, fuel regulator and filter (in tank as well) or the high pressure fuel pump. First thing is the 2 pumps in the tank. Have them tested to make sure fuel is getting to the HP pump at the pressure and flow required.

Finally the saga is over. Replaced the HP pump and all is good. Except the starter was going, service said the amp draw was high. I knew it was harder and harder to start and figured that it needed to be replaced soon anyway. So.... pull the intake and fuel rail and replaced the starter and now she starts right up. After almost a year of fighting with it it is finally over, updated tags and running good. Next up trans service and new plugs.

Here's the latest. Dealer service finally has agreed with me that it's the HP pump that is suspect. They are going to replace it under warranty. Next appointment is this coming Wednesday. So today, I'm out and about - taking it easy on it for fear of total failure and sure enough, it died from fuel starvation. Was able to get it to restart twice, enough to get it home but it has definitely given up. Acts just like it did almost a year ago when I replaced the last HP pump. At least I'll get some confirmation when it shows up on the back of a wrecker, huh? Hoping the end of the saga is nigh!

The service guy said when I got it done to come back and they would reset everything so I'm going to take him up on it, may work, may not. I'm with you Lewis, I think the new pump is bad. Didn't have this problem before the pump was changed and we've eliminated just about everything else. $250 an hour, and I thought $190 per was bad.

Well. got them replaced, went out for a test drive with Durametric running live on the HP Fuel Adaptation 1 and it started out at 0.79, good. After a couple of miles it started dropping eventually after about 7 miles it is back to the dreaded 0.69. HP fuel pressure still fluctuating back and forth over the set point. Another grand, same problem.

I hope your feeling is right. I already replaced the regulator and the filter so just the pumps and the L fitting are needed, $430 before shipping. I've already been in there so I'm familiar and the Pelican write up is pretty good but if I run into problems I'll give a shout.

The latest. This dealer has had it since last Wednesday, called today to say that the tech thinks it is the low pressure pumps in the tank. Well those haven't been replaced yet but tested fine previously. So off to replace another set of parts. Good news is the dealer has offered to match the prices I'm getting at the other dealer in NC. I guess I'm busy for a bit. He quoted $2900 to do the pumps, I declined. Indy quoted $1775, a lot better but still.... I can do it.

Went to another dealership to try and get the pump replaced under warranty but that was a no go. They wouldn't take my word for it (somewhat understandable) and told me they would have to test it to see if it had in fact failed. Well it was sitting on the counter in front of him so that posed a problem. The parts guy convinced me to make a service appointment so I went and talked with an advisor who feels confident they can figure it out although after a few minutes poking on his computer he asked if anyone had considered a camshaft slippage causing the error. Well no and I would think that if the camshaft had a problem I would be getting more than just a 1025 code being thrown. But I have an appointment on Wednesday for them to start. Needless to say I had to put the pump back on the car. Much more difficult with the intake manifold in place. I'll let you know what happens. If this one at least really looks at it it'll be an upgrade. Dealer is looking to get their classic Porsche credentials so maybe they'll be more focussed. Plus I have a friend who happens to know the service manager well and has given him a heads up, wish I had known that a few months ago.

Congrats, glad it fixed it. I'm taking out the old (new) pump and exchanging for a new one tomorrow. Hopefully that will fix it. Good luck on the trans, I just can't quite get comfortable with the wheels spinning on jackstands while I'm under it, brake jobs on this car are as easy as I have encountered, especially if you don't have to replace the rotors.

So after an extended conversation with the indy and data mining in his system, call to a dealership head mechanic who, in turn had a conversation with another mechanic we have concluded that the next course of action is to replace the replaced HP pump. Seems to be a regulator type problem and the reg is integral to the pump. Luckily the pump I have has a 1 year warranty and it's only been 9 months or so. Hopefully in a week or so I should have everything to get the next step done. Maybe the last step?

Yep, we did all of that 3 times. Every time the range 1 and 2 would eventually work its way back down to 0.69 and remain static. Before it would stick it would move around like you would expect within the specified range but within 40 miles or so it would drop and remain there.

Hmmm, I'll check with the indy (good relationship now) and see what he says. I know that to do the fuel adaptation it requires the immobiliser code. That's not something to mess with, even he was very, very careful when doing it and the value had to come from Porsche NA. I have mine now but wouldn't dream of using it, a $4000 DME isn't in my plans to replace. The pump isn't that hard to install, just tight space for one of the bolts. I had the intake off of mine to do the thermostat and water pump so it was really not bad at all. Just make sure you get all the broken plastic pieces out of there.

Unless it's the HP pump I don't think it is a fuel problem anymore, has to be some sensor somewhere that is causing the adaptation to go really low or is throwing a signal that the adaptation needs to be low.

Pressure and Flow tests on LP system were perfect. Still getting 1025 from Durametric, while it doesn't tell what it is, the guys from Durametric say it is the High Pressure Fuel Adaptation 1 and that is what the actual values are telling me. Value is 0.69 when it should be 0.72 or higher.

Well that wasn't it. Changed the fuel filter and the HP fuel actuals are still bouncing all over the place.

Wow that is exceptional. I didn't even give it a thought because of age and miles. Good for you. You'll be up and running before you know it. Not sure if you can do it or how the voucher works but I have been getting genuine Porsche parts from a dealer in North Carolina, Paramount. Their prices beat everyone and I mean EVERYONE and they are vin # driven, have a Porsche guy check compatibility and are generally good to work with. You ought to give them a look, https://store.paramountauto.com/auto-parts/porsche

In my research I found that when its gone its gone. Mine stumbled for a couple of days and then would not start, at all. The plastic part is merely a way to get the cam drive on while trying to stab the pump onto the mount. If it has disintegrated it may have caused other problems with the pump but I'm not sure. Mine was in about five pieces, had to assemble the puzzle when I got the parts out to make sure I had all of them. Mirror and an angled pick got it all out. That HP pump is pretty solid so I'm not sure that any lack of fuel from the back end would cause it any harm but who knows. And it's pricey too.

At this point I'm willing to try something. If I'm going to start parts chasing I guess the filter is as good a place as any to start. I'll hit the pumps next, if oil would get over $60 a barrel I would do both of them now. It may be fine but gotta start somewhere and this seems to be a logical step based on your logic of the hp fuel pump being erratic. Makes sense to me anyway.

LP fuel pumps aren't new but system was thoroughly pressure and flow tested. First thing the indy did. New clutch and $40 plastic cam stopper, sold separately.

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.

Brand new High Pressure Fuel Pump.

It runs fine except for the lope when it's cold, that smooths out all but faintly when it warms. Normal driving you don't notice anything wrong but a quick WOT will give it a slight cough and then it comes on like it is supposed to, fun filled.

Thanks for the reply Lewis. Yes the low pressure fuel delivery was fully checked, a new regulator was installed before all of this started. The high pressure side was checked too, the indy decided that one of the most sensible replacements would be the hp sensor on the fuel rail so he did that. But he did an extensive lp test according to the book and everything checked out good.

Hello All, Been around here for a bit though not often as this vehicle has been one of the most trouble free I have ever owned. 2009 Cayenne S, 105,000 miles. Never a major problem since I've owned it, couple of early issues dealer took care of. I have now reached a point where the thing has reached boat anchor status. Let me explain, lengthy. Back in June 2016 I had an error code from the thermostat not closing and the engine not heating fast enough for the smog stuff to work. Surmised using my Durametric and then proceeded to replace the thermostat and while I was in there the water pump as well. After that was done about a week later I had the dreaded high pressure fuel pump go slowly out until it wouldn't run. Useful forum here with the step by step replacement guide, replaced pump, everything great except now I'm getting a 1025 code on the durametric, which doesn't have a description. Talked to Durametric, great bunch if you ever need to deal with them, and sent some data files to them and they responded that it appeared to be the High Pressure Fuel Adaptation Value #1 and it was too low. When I looked at it on the Durametric it reads a steady 0.69, below the normal range of 0.72-1.50. This one throws the check engine light and I need an inspection of the car (Houston, smog) and it won't pass. So after much investigation into this part of the operation of the engine I finally gave up and went to an indy (40 years Porsche experience, pretty much all he does) and he of course has the PIWIS and reads out the problems, and after getting the immobilizer codes and what not from Porsche reprograms the DME to see if that will fix the Adaptation problem and the value is now dynamic and is within the range. Fixes it for about 20 minutes of run time, CEL comes back on and the value has again dropped to 0.69 and static. Went out into the mechanic only forums and asked questions to whomever would listen and got nothing back. So now we are into late December and still no resolution but still working on it, new high pressure fuel sensor, initially did a complete fuel delivery test, passed, smoke tested the vacuum system, passed. High Pressure Fuel set point and actual values were tracking like they should but Adaptation is still stuck at 0,69. Then when the new year rolled over Porsche NA has now decided to take all the Cayenne programming ability (and files) away from indys so overnight the file for my car is gone off PIWIS. Hmmm, now what: the dreaded dealership is the only option. There are a few here in a big city and the indy knows that the guys at one dealership are more experienced (i.e. old) than the others so I take it to them on Feb 2 and the service writer assures me they will fix it. So 5 weeks later after the only interaction I had with him was when I drove the 25 miles to the dealership to see him in person (no returned voicemails, no messages returned) 3 times but hey if he can fix it it will all be worth it, right? At one point he thinks it is the gas because it "smells bad" so I let it go another week. I show up yesterday and he says "Good News, it's fixed!) and goes and gets the car says it's running great but as I get into it I see the CEL is still on. He says "Oh, forgot to reset that" Gets the diagnostic computer hooks it up and while he's clearing the code shows me the Fuel Trim Adaptation Values and says "see they're close to one another (Bank1 and 2) so we're all good. I'm thinking to myself....well you can imagine. So I get in and am going to drive back home, pick up the wife and go back to get her car that I had to leave at the dealer. Needless to say on the return trip to the dealer, guess what happens. CEL light comes on. Service Dept closed while I was on the way back so that wasn't an option and frankly I don't think they did a single thing to the car. At least it was no charge or I would have been fighting mad. So I get the Durametric back out today and notice that the HP Fuel setpoint is fine at 40.0k like it should be at idle but the Actual value is jumping all over the place - above and below the setpoint. Hmmm what the.... I looked at it closer and after revving it a few times it seems to be going up and down in a rhythm (which would explain the surging idle) with high points above setpoint and lows way down below the 10.0k point So in summary does anyone, anywhere have any idea or have seen anything like this. I am trying to avoid the chasing it with parts much like the indy didn't want to start either. I'm going to have a conversation with the Service Manager at another (closer) dealership here that a friend knows this week and see if he has a clue and a course of action. Otherwise I'll have to put a chain on it and drag it down to the water.