# help! misfire issue at hgher RPM bwa 2.0tfsi APR K04



## kakluote (Nov 19, 2011)

I’ve got misfire at higher RPM (normal after 6000 RPM) for my apr k04kits bwa engine. Its quite annoying.

Here are the actions I have taken,


action taken:
1> unplug the maf sensor/ issue still exist but better (misfire counter 
1> drop from 50 to 20,idle rpm much stable)
2> find that most of the misfires come from C3, a little from C2 and C4
3> then, change the coilpack of C3 and C1--no help
4> change the spark plug of C3 and C1--better (ecu detect less misfire, 
4> but still can hear and feel car stuck a little bit around 6000 RPM)

So what should be my next actions?:

1. checking injectors ?
2. put stock maf back?
3. BTW: i use apr downpipe with OEM cat-back, will this combo be the flow limitation then cause misfires, why most misfire only come from C3?
4. Or misfire like 50 to 60 can be safely ingored?
5.also, i install rfd, will it bring un balance air flow by bad installation? 



waitting for your comments...

appreciate it.


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## TTAdict (Aug 3, 2010)

Before checking injectors i would like to recommend you running the stock file first and then see what will be happening. Good luck


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## kakluote (Nov 19, 2011)

stock tune with s3 injector ?


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## theGLIguy (Dec 2, 2011)

Sounds like fuel supply issue. Stock pump in the tank and stock HP fuel pump as well?

If it is a fuel issue, I would stop running it that high before it burns up


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## TTAdict (Aug 3, 2010)

The idea is to put the car into stock to test it under stock engine load.
If it duplicates the misfires under the stock file then you have to log fueling (LPFP and HPFP)
Good luck


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## kakluote (Nov 19, 2011)

TTAdict said:


> The idea is to put the car into stock to test it under stock engine load.
> If it duplicates the misfires under the stock file then you have to log fueling (LPFP and HPFP)
> Good luck



to stock with s3 injector, that will be too rich..


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## 02GTI-VR6-same1 (Nov 18, 2004)

theGLIguy said:


> Sounds like fuel supply issue. Stock pump in the tank and stock HP fuel pump as well?
> 
> If it is a fuel issue, I would stop running it that high before it burns up


Any significant fuel supply or inability to meet a/f ratio would be met with instant limp mode. Sounds like typical Intake/MAF/APR tune issue to me...with the understanding that no "issue" has necessarily been acknowledged other than poorly matched or performing hardware.


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## ROH ECHT (Dec 9, 2010)

Do you have any codes and/or graphs to post? Without them I could only guess it is the 1st O2 sensor or injectors given what we have to read for now.


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## Starrgti (Apr 3, 2012)

This sounds a lot like what's happening to me… I've changed the intake back to stock box but it doesn't solve the problem… I have the logs but can't figure out how to upload them...


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## ryan mills (May 3, 2002)

I thought that weak exhaust springs was the issue with the k04? My buddy and I chased a cylinder 2,3 misfire for weeks and found that the valve springs were the issue due to the high back pressure of the k04 turbo.

The issue happened at over 5800rpm in third gear+. we changed coils, plugs, and injectors multiple times without success. APR offered a neutered k04 file that solved the issue, but it was a bit weaker.


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## kakluote (Nov 19, 2011)

ryan mills said:


> I thought that weak exhaust springs was the issue with the k04? My buddy and I chased a cylinder 2,3 misfire for weeks and found that the valve springs were the issue due to the high back pressure of the k04 turbo.
> 
> The issue happened at over 5800rpm in third gear+. we changed coils, plugs, and injectors multiple times without success. APR offered a neutered k04 file that solved the issue, but it was a bit weaker.



yes buddy, the weak valve is indeed the issue.

mine has been sloved by replace them


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## kylegti07 (Apr 4, 2012)

what exhaust valves did you replace the stock ones with??? and which year of car is yours? i had the same issue on my apr stage 2 bpy gti. it went away when i integrated my stock maf into my aftermarket intake. i still get the shudders/misfires intermittently and i thought plugs would fix it but after your post i think its the exhaust valves......


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## T0neyDanza (Apr 25, 2007)

kylegti07 said:


> what exhaust valves did you replace the stock ones with??? and which year of car is yours? i had the same issue on my apr stage 2 bpy gti. it went away when i integrated my stock maf into my aftermarket intake. i still get the shudders/misfires intermittently and i thought plugs would fix it but after your post i think its the exhaust valves......


Run NGK PFR7B plugs. They are pricey, but are gapped at .028 and fixed all my misfire issues. I have had the same issues as everyone else and been pulling my hair out trying to figure it out.


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## kylegti07 (Apr 4, 2012)

are those the stock heat range plugs?? i have ngk's from the dealer, so stock heat range since this is what apr recommended. appreciate the input!!


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## ryan mills (May 3, 2002)

The exhaust valves themselves are fine, it's the valve springs that it s the issue. Integrated Engineering makes a kit for the TSI motor with springs and new retainers that takes car of the issue. Some people say that plugs are the issue...If your car has a ton of miles, it might help, but it didn't for me.


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## kylegti07 (Apr 4, 2012)

ya i meant to say springs, and i have an fsi engine so the ie springs may not work. also many people say that some of the fsi engines were ok and built a little stronger than others, especially the tsi, im leaning to my issue being plugs because once i regapped the plugs down to .028 there were fewer misses. im wondering if the plugs (NGK PFR7B) that TOney Danza recommended are the stock ones or if they are a heat range colder???


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## Bunnspeed (Apr 2, 2013)

kylegti07 said:


> ya i meant to say springs, and i have an fsi engine so the ie springs may not work. also many people say that some of the fsi engines were ok and built a little stronger than others, especially the tsi, im leaning to my issue being plugs because once i regapped the plugs down to .028 there were fewer misses. im wondering if the plugs (NGK PFR7B) that TOney Danza recommended are the stock ones or if they are a heat range colder???


I think they are probably a heat range colder than stock, but don't quote me. I'd google "oem (or "stock") mkv gti spark plugs" and see what comes up. Pretty sure if the NGK that comes up has an "8" in it, that means the stock plugs are a heat range hotter than the PFR*7*Bs, but then again I might be talking out of my butt here.


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## kylegti07 (Apr 4, 2012)

ok ill check that only reason i was asking why toney recommended them because apr specifically says to stay with stock heat range....


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## Tutti57 (Jun 20, 2011)

Haven't most apr issues been linked to the intake not playing well?


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## kylegti07 (Apr 4, 2012)

Tutti57 said:


> Haven't most apr issues been linked to the intake not playing well?


yup that is totally true!!! and that is why i am running a stock maf body integrated into my k&n intake. basically from the turbo to the maf housing its all stock then from the maf there is a 12" long 3'' id urethane tube followed by the remaining portion of my K&N intake and filter. this system works really well and flows great! im pretty sure my plugs need changing tho cause i have regapped them twice now and after only 8k ugh and for your info i am running the stock ngk's from the dealer but i am unsure if i should go colder or not.....


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