Qwoz
Roflcopter pilot
- Location
- Redmond WA
- Car(s)
- 08 GTI
Hey guys, right now I am kind of stumped but I feel that I am getting close to finally sorting this out and I just wanted to see if we have any gurus still on the forum that would be able to make sense of this fueling issue.
To start let me summarize the situation.
About 2 years and 30,000 miles ago I got an upgraded fuel pump (HPFP Upgrade brand) off the forums here used, and went APR stage 2+. After about 800 miles I started getting a P2293 Code (Rosstech says N726 fuel pressure regulator related). I changed the fuel filter, which didn't help. Since the code was only showing up every so often I decided to forget about it because it was the only code, and I had no performance issues whatsoever. I have always kept my cam follower up to date and my car is a 2008 FSI with a Rev B camshaft, so that is not the problem.
Fast forward to now, I have some money to spend on fixing up the car and I have decided to keep the car as long as it is running well (currently 83,000 miles), and I want this pesky code to F*%k off
addle: I hadn't scanned the car in a while, but the CEL has been showing up with increased frequency. Over the past few months when scanning with VCDS I have come to find out that I no longer throw the P2293 code, now it is only the P0087 code (Fuel Rail/System Pressure - Too Low). What is unique about this, as far as I can tell from reading everything I can find, is that the frequency for which I throw this code is much greater that other occurances. For example, when I haven't scanned for a day or two, when I go to scan it says the code has been thrown around 30 times. Almost like this code is thrown every time I start the car. Most people get this code at high RPMs.
I still suffer no drivability issues, which almost makes solving this thing worse because it feels like im chasing a ghost.
OK, so what have I tried to fix it:
I replaced the fuel pressure sensor on the HPFP, this did not solve it. I have noticed that my low pressure fuel pump has been whining more than usual. For the past month or so I have been able to hear it while idling. It makes somewhat of an oscillating whirring noise. This led me to believe I should replace the LPFP and controller. I did the controller first, no help. Just last weekend I replaced the LPFP and ran the VCDS adaptation, guess what... still no help. In fact this new pump is LOUDER than the old one. Sounds like an electric tooth brush turning on when I open the drivers side door. As far as I can tell it is supplying enough fuel, but it does do this weird thing where it won't turn off for a few mins after I shut the car off (continually buzzing when the key is out). I still get the same code and occurrence, so this leads me to believe the issue is not the LPFP.
So basically this has narrowed it down to a few things -
-Upgraded HPFP is faulty. I kind of doubt it because car drives great, no cuts. However, I did get the P2293 when I first put this on, but that code seems to have gone away.
-Fuel filter needs replaced again. I have been driving the current fuel filter for 30k.
-High Thrust sensor needs to be replaced, which is the fuel pressure sensor on the fuel rail.
I am totally new to VCDS logging so I'm not really sure what I am doing, but when I got home today I decided to log group 103 (related to fuel pressure) when starting the car up because I have a hunch this is when I am throwing the code. I have supplied a link to the excel file of the log with notes in the margin, and highlighted values that stand out to me. What I am seeing essentially is that the fuel regulation value is dropping by a lot about 10-30 seconds after start up, and this is then causing the LPFP to compensate for the dropping pressure by boosting the BAR pressure all of a sudden. I have no idea if this is normal behavior, possibly an adaptation of sorts, or if this means sometime more insidious. I will tell you that I did not notice the old LFFP doing this, but it could have been because it was so much quieter. I am 75% sure this is when the code is being thrown, because I cleared the code and then started and stopped the car a few times to do this log, and the code came back on.
I really hope someone has the interest and time to take a look at this. Think of it as holding on to the last piece of a jigsaw puzzle, and you are about to walk up and press it into place :lol: ... However it might not be that easy and I applaud you for your efforts in solving this riddle. I am open to any and all suggestions.
VCDS Excel File - https://drive.google.com/file/d/0B6uIwVFRn3TBaGFES0h6Ri1DdDQ/view?usp=sharing
To start let me summarize the situation.
About 2 years and 30,000 miles ago I got an upgraded fuel pump (HPFP Upgrade brand) off the forums here used, and went APR stage 2+. After about 800 miles I started getting a P2293 Code (Rosstech says N726 fuel pressure regulator related). I changed the fuel filter, which didn't help. Since the code was only showing up every so often I decided to forget about it because it was the only code, and I had no performance issues whatsoever. I have always kept my cam follower up to date and my car is a 2008 FSI with a Rev B camshaft, so that is not the problem.
Fast forward to now, I have some money to spend on fixing up the car and I have decided to keep the car as long as it is running well (currently 83,000 miles), and I want this pesky code to F*%k off
addle: I hadn't scanned the car in a while, but the CEL has been showing up with increased frequency. Over the past few months when scanning with VCDS I have come to find out that I no longer throw the P2293 code, now it is only the P0087 code (Fuel Rail/System Pressure - Too Low). What is unique about this, as far as I can tell from reading everything I can find, is that the frequency for which I throw this code is much greater that other occurances. For example, when I haven't scanned for a day or two, when I go to scan it says the code has been thrown around 30 times. Almost like this code is thrown every time I start the car. Most people get this code at high RPMs. I still suffer no drivability issues, which almost makes solving this thing worse because it feels like im chasing a ghost.
OK, so what have I tried to fix it:
I replaced the fuel pressure sensor on the HPFP, this did not solve it. I have noticed that my low pressure fuel pump has been whining more than usual. For the past month or so I have been able to hear it while idling. It makes somewhat of an oscillating whirring noise. This led me to believe I should replace the LPFP and controller. I did the controller first, no help. Just last weekend I replaced the LPFP and ran the VCDS adaptation, guess what... still no help. In fact this new pump is LOUDER than the old one. Sounds like an electric tooth brush turning on when I open the drivers side door. As far as I can tell it is supplying enough fuel, but it does do this weird thing where it won't turn off for a few mins after I shut the car off (continually buzzing when the key is out). I still get the same code and occurrence, so this leads me to believe the issue is not the LPFP.
So basically this has narrowed it down to a few things -
-Upgraded HPFP is faulty. I kind of doubt it because car drives great, no cuts. However, I did get the P2293 when I first put this on, but that code seems to have gone away.
-Fuel filter needs replaced again. I have been driving the current fuel filter for 30k.
-High Thrust sensor needs to be replaced, which is the fuel pressure sensor on the fuel rail.
I am totally new to VCDS logging so I'm not really sure what I am doing, but when I got home today I decided to log group 103 (related to fuel pressure) when starting the car up because I have a hunch this is when I am throwing the code. I have supplied a link to the excel file of the log with notes in the margin, and highlighted values that stand out to me. What I am seeing essentially is that the fuel regulation value is dropping by a lot about 10-30 seconds after start up, and this is then causing the LPFP to compensate for the dropping pressure by boosting the BAR pressure all of a sudden. I have no idea if this is normal behavior, possibly an adaptation of sorts, or if this means sometime more insidious. I will tell you that I did not notice the old LFFP doing this, but it could have been because it was so much quieter. I am 75% sure this is when the code is being thrown, because I cleared the code and then started and stopped the car a few times to do this log, and the code came back on.
I really hope someone has the interest and time to take a look at this. Think of it as holding on to the last piece of a jigsaw puzzle, and you are about to walk up and press it into place :lol: ... However it might not be that easy and I applaud you for your efforts in solving this riddle. I am open to any and all suggestions.
VCDS Excel File - https://drive.google.com/file/d/0B6uIwVFRn3TBaGFES0h6Ri1DdDQ/view?usp=sharing
