# APR Stage II problems (no upgraded HPFP) with 06 GTI FSI 55k miles



## MA_GTIMKV (Feb 27, 2008)

Hello all,

Patient:
2006 GTI MKV GTI FSI 6MT 2.0T
APR Stage II with test pipe file (no hpfp)
Brand new "d" diverter valve
Upgraded PCV with Eurojet PCV Fix on it
Re-seated all intercooler hoses last week
APR downpipe with 100cell cat
OEM intake with K&N drop-in (same issue with OEM intake and paper filter)
New cam follower 10k ago, been stage II for ~30k now, stage I for 10k before that.

Problem:
WOT gears 3-6 I am spiking 19-20psi at 3k RPMs and then boost drops immediately to 14-15 and bounces around between 14-16 before regaining stability above 5k RPMs. Car feels like it hits a wall and you can feel the boost pulsations at WOT on the highway. ESP on or off does not matter. Much worse in cold weather as its breathing better but it seems fuel is off. But that might just be me. 

Resolution help!...
I have a newish OEM HPFP in the mail right now with a newer fuel pressure sensor on it as well. All diagnostics with fuel pump work out with vagcom diagnostics but I have not logged fuel pressures just yet at WOT. I'm hoping the newer OEM HPFP fixes these issues.. feels like a fuel cut but its not very pronounced just leaves the car feeling very flat when it hits full boost. Been having this problem for a year or so now, it just comes on very strong and worse in the cooler months for some reason. 5th and 6th gears are the worst but now 3-4 are doing it too. Sometimes 2 even cuts for a brief second but it could just be wheel spin. 

What can I log to see if I am having fuel issues? Will report back with the newer OEM fuel pump installed with a different fuel pressure sensor as well. Really just feels like it chokes itself at WOT for a few seconds and then regains a little but not as it should. 

Please help!! I have vag com and can log, but i'm a noob and need help with what to log!


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## BsickPassat (May 10, 2010)

Shoot a PM to [email protected]


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## ghita.silviu (Oct 26, 2010)

you will find how to do some logs here:

http://www.goapr.com/support/datalogging.php


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## dubTography (Aug 29, 2008)

cam follower  you didz it!


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## MA_GTIMKV (Feb 27, 2008)

not sure what that means.. but yes I did change the cam follower about 8k miles ago. That cannot be dead yet, first one was changed at 45k and had barely any wear


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## amckernon1028 (Apr 14, 2009)

Get an APR hffp and I your problems will go away. Your stock pump sucks, nut up and put the right pump for your tune.


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## crew219 (Oct 18, 2000)

amckernon1028 said:


> Get an APR hffp and I your problems will go away. Your stock pump sucks, nut up and put the right pump for your tune.


A lot could be wrong with the fueling system to create a fuel cut but SII software is not it. SII is designed around the limitations of the factory HPFP. It is very possible that the solenoid on his OEM HPFP is failing (common), or that his LPFP isn't supplying enough fuel to the HPFP or that the fuel filter is restricting flow from the LPFP. 

If the OP has no intentions to go SII + upgraded HPFP, there's really no reason not to purchase another OEM HPFP.

That being said, his issues could also be caused by bad coilpacks. The ECU senses the misfires and reduces N75 duty cycle and closes the throttle plate momentarily. 

Dave


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## MA_GTIMKV (Feb 27, 2008)

^^ thank you! You are on the same page I am thinking. I have no intentions of upgrading to II+ until I fix this problem. If the new OEM HPFP works then I may just get the rebuild.. but I'd hate to upgrade only to find the problem still exists or is worse! 

Coil packs are brand new and not the issue. Plugs are new as well.

Still haven't had chance to install new HPFP.. fingers crossed that is the problem.. :wave:


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## MA_GTIMKV (Feb 27, 2008)

for all those following or with similar issues here was the fix:

Followed the cam follower DIY to replace fuel pump. Ended up finding the banjo bolt that I didn't have the right tool for so I changed out all the sensors with new ones from my (slightly used) new OEM pump. While I was pullings things apart I found the metal fuel line on the bottom with the 2 nuts on it was LOOSE. Apparently the guy I had check the follower (local shop) last year did not tighten the fuel line and when I hit peak boost/power fuel would not hold pressure in that line. It's either that or the fuel pressure sensor which I also replaced from the newer pump. Anyways, put everything back together, primed the pump and it is good to go. No more cuts at WOT, gas mileage has been restored. 

So far my issues with mechanics:
1) Broken diverter valve clip (electrical connector fell off and caused crazy symptoms which took me months to figure out)
2) Loose fuel line on HPFP
3) Loose lugs (one from each wheel fell off in 1 day after tire installation)
4) Busted engine cover

Moral of this story, stick with DIY. I HATE people touching my car and/or house and now everything is DIY. Thank God for the internet. Good luck everyone - and keep those DIY rolling! Now I just need one to install/balance tires ;-) haha, hate people changing those too.


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## StuMacLean (Aug 9, 2003)

Just out of curiosity, how did you diagnose that issue? Did the HPFP area smell of gas after driving? 

Really just curious.

DIY FTW :beer:


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## MA_GTIMKV (Feb 27, 2008)

After many months of fixing things recommended from the forums and trial and error really. I ended up narrowing it down to the HPFP or the fuel pressure sensor.. so I bought a used OEM pump off here with the sensor on it. Ended up just replacing the sensor and discovering the loose fitting on the fuel line in the process. Learned how to change my follower while I was in there too, except for that silly banjo bolt that sucks. 

Boost gauge helped me figure it out too.. and some vag com logs, although they were fairly inconclusive since the problem came and went randomly. 

Self diagnosing sucks.. but it sucks more when the dealer cant' figure out the problem... OR in my case makes things worse. :bs:


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## StuMacLean (Aug 9, 2003)

Cool. But what exactly did you notice that showed you the fuel line bolt was loose? Was it rattling, or did you smell gas?


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## MA_GTIMKV (Feb 27, 2008)

oh, I was disassembling the OEM HPFP to replace it with a new one otherwise I never would have found it. Car did smell of gas after high RPM driving (spirited or highway at 80+)

It was just spitting a little fuel at WOT, other than that it really was holding quite well. Just give the lines coming out of your fuel pump a tug or perform the cam follower DIY and it covers removing the main fuel line so you can get the pump out to inspect the follower. 

It really was just a freak thing, and shady mechanic working on it.


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## StuMacLean (Aug 9, 2003)

Gotcha. Thanks for following up.


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## MA_GTIMKV (Feb 27, 2008)

update: ... problem came back today even after having a great last week of good power. I guess it wasn't the fuel pump? Either that or it is actually the pump itself as I replaced all the sensors and it was working fine... maybe I will finish the job once I can figure out how to get the damn banjo bolt off... :thumbdown:


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## OmegaRed1723 (Oct 10, 2008)

It's a bit a drive from you (about an hour), but you might wanna try Jesse over at Banchwerks in Pawtucket. He's an excellent young VW mechanic, and priced reasonably. He'll help you diagnose your issues and there isn't much he hasn't seen.


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## superacerc (Jul 6, 2010)

I've got the same issue @ 44K miles. Only difference is I'm stage 1 APR. Exact same symptoms and the cold weather seems to bring it about. I've got new coil packs, a new cam follower(old one wasn't really that bad) and my fuel pump connections are tight. I'm going to try replacing the fuel filter and next i'm going to go to the APR HPFP (i want to go 2+ anyway). 
I'll update if i find the correct problem. Only thing i can think of is the filter for now though or maybe my fuel pump is acting up.


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## MA_GTIMKV (Feb 27, 2008)

mine is happy for the moment. I changed out my follower and replaced the thrust sensor on the fuel pump and all is happy. But oddly enough, when I to a throttle body alignment my symptoms come back. What the hell?


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## superacerc (Jul 6, 2010)

*Same on STG 1 and Stock*

I switched back to stage 1 to see if it was the amount of fuel that was causing the issue but I've still got the same cut out on stock. Either it's a different problem alltogether or the fuel pump is getting worn out. My cam looked ok when i pulled the follower though so I don't think it's that. VW just replaced my coil packs under recall about 3 months ago. I don't have a Boost Guage so I can't tell what it's doing there.


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## MA_GTIMKV (Feb 27, 2008)

my problem got better... then today it was -7 on my way to work and my boost was bouncing all over the place at full throttle. Didn't want to push it too hard since it was so cold and my clutch would probably slip in these temps.


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## 16 Valves of Fury (Jun 13, 2006)

Reading your initial post I was kind of leaning towards a clutch issue as the cause of concern. I am having slippage problems @ 46k w/ stage 2 APR and at first it was hard to detect because it would slip for only 500 rpms or so then slowly come back. If all fuel logs seem OK and you have covered all other known boost issues, then watch your tach closely. They tend to slip more in colder temps as you stated but mine has actually been slipping intermittently. I think this could be perceived as a "fuel cut" or boost problem as the engine is no longer transmitting power properly which could do funny things with your boost gauge.


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## superacerc (Jul 6, 2010)

*Clutch Slip?*

I suppose that would still be relevant to me even though I'm DSG since it's still operated as a manual just with twin auto clutches. Definitely possible i suppose. I've heard of people with stage 3 that had no issues with DSG though. Wondering how much of a possibility that would be.


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## U.G. MKV (May 31, 2010)

I'm having the same symptoms but I'm Revo stg2. And just as described it's worse when it's cold. I was leaning towards the fuel pump too but I've had the same mods for three years with zero problems. Could it be that the HPFP is just worn out? I have new coilpacks new follower" old one was fine" and new spark plugs. This is really annoying. :banghead:


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## U.G. MKV (May 31, 2010)

Nobody?!?!?!?!?


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## U.G. MKV (May 31, 2010)

Nothing?


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## Krieger (May 5, 2009)

could be the sensor as said above, or the camshaft itself, as described in 10.9 BILLION threads across the interwebz.


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## U.G. MKV (May 31, 2010)

It's 11 billion thank you.


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## Krieger (May 5, 2009)

lol. :beer:

no, really though, run some logs if you could and see if its meeting demand, and if not, check to make sure the LPFP and whatnot is keeping up.


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## theguy1084 (Feb 4, 2007)

crew219 said:


> A lot could be wrong with the fueling system to create a fuel cut but SII software is not it. SII is designed around the limitations of the factory HPFP. It is very possible that the solenoid on his OEM HPFP is failing (common), or that his LPFP isn't supplying enough fuel to the HPFP or that the fuel filter is restricting flow from the LPFP.
> 
> If the OP has no intentions to go SII + upgraded HPFP, there's really no reason not to purchase another OEM HPFP.
> 
> ...


I had simular issues with mine as well. Also sometimes it would seem to sputter and miss under a 3 or 4th gear pull. It came up with a low fuel pressure fault and the dealer replaced the pressure sensor. About a month later I had the same issue but the dealer couldnt find a problem with it. I ordered an APR HPFP shortly after and havent had any issues since.


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## rippie74 (Sep 26, 2007)

amckernon1028 said:


> Get an APR hffp and I your problems will go away. Your stock pump sucks, nut up and put the right pump for your tune.


Exactly


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