ybe

I can hear my pump sometimes but it more like a turbine or winning noise. Even though all connections are correct there have been stories of hoses coming loose in the tank from the pressure after driving

4 hours ago, lewisweller said:

Yep I already order one from us 52 dollars. 

 

I don't follow your email maybe some typos there? AOS yes I've had it out twice it isn't leaking or damaged. What was the other one? Control arm bars? 

Email?? Yes I believe it was the rubber seal/gasket peice that attaches the control arm bar to the engine it can crack basically loosening and can cause vibrations roughness and such but don't know If this is related to your problem but I'd check also since u been in doing 1000 other things anyway 

Yea I'd go ahead and replace that next since it's one of the cheapest and seems like u accessed it pretty quickly one thing about the cps is that it will work intermittently when it goes bad. kinda like the fuel pumps. 

Another thing that comes to mind would be to check the AOS brain. And I also recall reading a rough running Cayenne story were the guy replaced a lot of parts and said something about it being the control arm bar the rubber gaskets they were brittle and eroded he replaced so check the rubber on your control arms for cracks, erosion you could probably find the post search around

Yea I was going to mention it's possible but I know people have messed around with the dme/ecu to no avail or it was temporary fix worth a try I guess pretty much loss without code that's the hardest thing about Porsches the no code faults leaves you with nothing but a process of elimination.. it's why a lot of people get rid of them 

Man..... now I'm wondering If it's something that's simply being overlooked like those 'BERU' coils what brand are your MAFS?

Yea next up would be the crankshaft sensor if u search around the forums u can probably find the guys posts went through much of what u did then finally changed the crankshaft sensor and solved it. He had similar symptoms.

I've also heard people throw around ignition switch causes wacky issues like this but not sure how wouldnt be my first place to look

Also keep in mind 1 of the aftermarket parts u installed just may not be functioning its happened before it's why some techs rule against 

18 hours ago, lewisweller said:

12 hours ago, lewisweller said:

No my test means both pumps are running but not sure how well. 

Where is this check valve in the engine bay? I can't see anything there and nothing on any diagrams or parts mentioning this, I thought the only check valve is in the fuel filter and or the regulator? 

Oh ok I thought you said it does die when you pull fuse 14. It's not a check valve I think its a fuel purge valve something like that I'd have to find it but if you say your 2 fuel pumps seem to be working then yea check hoses replace the right side and if no solution it's probably your MAF which can cause the RPM fluctuation and other weird issues you are describing.

I'm no expert but after Fuel pumps/purge valve and MAF the only other things that I can think of over the years of everything I've read on Cayennes that can cause these symptoms would be the TPS/crankshaft position sensor or the camshaft pos sensor, or Battery either that or something is hooked up wrong or a new part is not functioning I know some Porsche techs recommend against using VDO also something to do with having to replace same part over and over

1 hour ago, lewisweller said:

I just went down to the car to check if it is actually running the left side pump (half tank of fuel still) just in case it failed but nope I pulled the fuse and it does die. Then cycled the ignition and started on right pump engine run the same ok idle as was on the left pump. 

I then replaced the left pump fuse and switched off again. 

Did the throttle reset sequence as this sometimes has by fluke or not made the car run better for a short time at least. But after restart its the same idle and has the same stumbling rpm at 1000 and around 2-2200 rpm. Its like at that particular rpm it vibrating more and doesn't sound happy or clean revving, I didnt go for a drive though. 

 

What I do notice is I have a lot more ticky almost direct injection diesel type rattle and tap, feeling the injectors rail there is what feels like more vibration than I would expect or can remember feeling before. Testament to low pressure quite possibly?

 

Also that tappy ticky noise is what I here at low rpm acceleration when it stumbling up through the rev range, pinking sound "pre detination" perhaps cause of the lean mixture. 

 

Anyway until I get the right pump replaced on wednesday and recheck all piping, I won't be able to rule out that as the cause. 

 

On hinds sight I should have gone to a garage a long time back and done a pressure test before going down this road. I'm pis*ed off I could not find the simple fittings here to make my own kit and could only find a whole kit that was the same cost as the two pumps anyway. Lesson learned! 

I feel your pain man I'm going through the same. Mine runs on right side fuel pump fine. It seems like from what you are saying that your left fuel pump is not running at all so it is either a dud or something has been hooked up wrong. Make sure u recheck the work. A Hose(s) or ground may have came lose, hose may have been hooked up incorrectly or may have leak in right side hose as u indicate.  Don't forget there is a fuel check valve in the front of the engine as well that can cause similar issues. I think my issue is left fuel pump only since it will run almost normal with fuse 14 pulled. 

At this point sounds like process of elimination like with similar to mine recheck hoses replace right pump, replace check valve, replace MAF(s) in that order keep in mind I had these issues and Porsche dealer told me my car was fine then told me it was the MAF when it clearly wasn't other small indy shops couldn't figure it out either clueless techs

25 minutes ago, lewisweller said:

Bad news in fact the better running lasted for two days only and then it all came back like some bad nightmare. 

I don't know what happened but I have some theories that the right side pump non return valve inside the pump is leaking the pressure off from the left pump or I got a pipe somewhere in there split or I'm totally wrong and it's nothing to do with the fuel. 

 

For the sake of ruling out all fuel related issues now and for the foreseeable future I own the car I have already bought a new right side pump which I will install on Wednesday as I'm trying to run the tank back down to empty nearly. 

 

I have new filter and regulator with flange gaskets a few months back. 

 

I found a great diagram from someone else's post about fuel pump issues. 

Notice the red line from each pump that joins before going to the filter, my theory is if the right side pump is not running (ie usual part load driving and not too low fuel level) and the check valve built inside is leaking, the pressure and flow from the left pump is bleeding off and doesn't deliver correctly to the engine. 

Possibly when I did the left pump swap I inadvertently mad ethereal check valve work for a little while and then it started leaking again. 

It's a far fetched but possible theory I have to eliminate now. 

 

The only other thing I can think of is the turbo breather pipe at the rear is leaking for sure but that little bit of air can't do all this sporadic running problems and an ok idle and high rpm rev with a stumble at around 1000 and 2000 rpm when stationary parked holding the rpm is just not making any sense. 

 

My mind has run through so many possibilities and I've probably read over 2000 posts and technical informations about everything A-Z. I'm so sick of reading a long thread which ends with.... "and then I read the very helpful DTC code and replaced the coils and all was fixed" ahhhhhhggg if only it was that simple for me. 

 

Often times when you replace the left fuel pump and drive around a few days and then symptoms return. It's usually because somewhere a long the line of the install something was hooked up incorrectly. Or maybe the right pump finally gave out altogether. Given your symptoms It is generally 5 things it could be. Fuel Pump/Valve related, MAF related, TPS, Camshaft/sensor related, Coils....

1st course of action should be making sure your right fuel pump is still functioning and before replacing make sure the left pump hoses are hooked up 100% correctly. As a matter of fact test your left fuel pump is functioning as well some aftermarket pumps have gave out 48 hours after installation.

LOL well I told you it was the left fuel pump.. It was pretty easy to identify for me when reading your symptoms. But just keep in mind in time generally you want to replace the filter flange or at least clean the filter when you replace the left fuel pump because a dirty or clogged filter may have been an issue and can cause an issue with your new pump over time. And you will want to replace your right pump as well after a while because the fuel pressure is probably lower than normal or let's say not in sync with the newer pump...

If you pulled fuse 14 and your vehicle died then your left/Driver side fuel pump is dead. I'm in the same boat. I use to have cut out on acceleration and stuttering problems all kinds of issues than read up on it and discovered my driver side fuel pump was dead after pulling fuse. Even Porsche dealer did not figure it out and told me it was the MAF and tried to charge me 2800 to fix! There is no telling how long I had been driving on 1 pump with the main pump either partially running or dead but I'd say it's been at least 6 months to a year. Plan to fix it next week.

The thing that had me fooled was my PIG would drive fine for about an hour until the pump warmed up then it was start acting crazy upon accel cutting in and out and such so it can appear as If your pump is running correctly when it's not 

On 1/3/2017 at 1:09 PM, lewisweller said:

How could a faulty fuel pump or a filter for that matter create fuel smell outside vehicle? Are we talking fuel vapor escaping or rich exhaust smell? 

 

Renzo what was the bad running symptoms please? 

Did it run well when cold and then bad when warmed up or hot? 

Usually the filter develops a leak or hairline crack that may not be visible. raw fuel begins to seeps through and that is where the fuel smell comes from. Every vehicle is different. Mine ran fine with fuel filter leak but fuel smell was really strong after drives when I park I could smell raw fuel towards the rear where the filter is. Depending on how bad the leak or crack is determines how well the car will run. From my experience when filter needs replacing the main driver side fuel pump will not be far behind.  

FYI If you did not replace your fuel filter when replacing both fuel pumps, then you will most likely encounter this problem again and the fuel smell will return.

When I had a strong smell of gas it ended being the fuel filter. There was a strong smell of gas on the driver side towards the rear.

When I had a strong smell of gas it ended being the fuel filter. There was a strong smell of gas on the driver side towards the rear.

On 12/5/2016 at 9:48 AM, lewisweller said:

404 is one of the fuel pump relays I guess the one you pulled was the left primary. FYI fuse 13 is left pump and fuse 14 is right side pump both 15 amp. 

The system uses the left driver side pump as the "primary pump" this pump is likely dead or a fuel line is broke between the pump and the fuel filter or something else strange is going on. Anyone been in there for any work? Previous related service history, model and mileage is helpful.  

 

Removing the fuse and/or relay automatically makes the other pump run on the right passenger side (assuming left hand drive). 

I bet if you had a low fuel level it would run with the both fuses and relays connected this is because below a certain fuel level both pumps run. Somewhere below 1/4 tank and the fuel light coming on both pumps will be running. 

 

So verdict is either a pump problem or associated component of the pump is the problem. One guy replaced his pumps and got some fuel pipes squashed, another connected the pipes wrong somehow, another guy had cracked pipes which only broke when he installed new pumps and that threw him off until he stripped it all out again. 

 

Of course do your Diagnostics to confirm this before spending out. 

Might be an opportune time to do some other service items like full filter and regulator as a dead pump would mean it done some service life already I'm guessing. 

Don't forget 2 new rubber Seals or you will regret it. 

Are you sure you don't have fuses mixed up? I'm currently on 1 pump in my CS with fuse 14 pulled and can hear the right side pump running/whinning when the car is on. I think Fuse #14 is for the driver side pump and #13 is the right pass side pump, but feel free to correct me If I'm wrong USA