# 2001 audi 11 225 roadster over boosting and stutters while doing it.



## bodya2004 (Feb 21, 2009)

The car is 2001 Audi tt roadster quattro.225, 99.***k, apr chip, downpipe, fmic, intake, forge dv, boost gauge.
The car starts normal, drives normal no problem but as soon as i go open throttle full boost it spikes to over 25psi and stutters a bit not pulling. Just replaced the line going from n75 to wg and it was good no change. 
I have replaced, maf, coils, plugs, fpr, n75, dv. Could it be software but i don't think so, possibly wg got stuck not sure any idea how to test it. anything will help.


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## darrenbyrnes (Jan 4, 2005)

bodya2004 said:


> The car is 2001 Audi tt roadster quattro.225, 99.***k, apr chip, downpipe, fmic, intake, forge dv, boost gauge.
> The car starts normal, drives normal no problem but as soon as i go open throttle full boost it spikes to over 25psi and stutters a bit not pulling. Just replaced the line going from n75 to wg and it was good no change.
> I have replaced, maf, coils, plugs, fpr, n75, dv. Could it be software but i don't think so, possibly wg got stuck not sure any idea how to test it. anything will help.


Mine has started doing that as well, but only on cyl #3. I'm going to swap in a new wiring harness (but they are on backorder at ECS - March 20 ETA).

Have you run VCDS (Vag Com) on it to see if you have any faults / misfires??


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## Marcus_Aurelius (Mar 1, 2012)

Sounds like a misfire under high boost to me. You said that you changed the plugs but at what gap?
From experience, the weak spark in our cars could get blown off under high boost( 25+ psi) if the gap is too wide. It will idle and run fine at low load and partial throttle but misfire at high boost. In my car for example at 30+ psi, I have to run a .025 "gap in the streets to prevent misfires. It is even more emphasized at the track where nothing bigger than .022" gap will make the car break-up under heavy boost/throttle.

The other thing it could be is your wastegate creeping open at those higher pressures. You would also notice the boost fluctuate when it happens.


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## bodya2004 (Feb 21, 2009)

Yeah i will chack e the plugs again but the problem i have is that i dont want that much boost also i want no more then 23 just to be safe. How can i check if its the waste gate and way to fix it??? Tnx guys


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## murTTer (Jun 27, 2009)

bodya2004 said:


> Yeah i will chack e the plugs again but the problem i have is that i dont want that much boost also i want no more then 23 just to be safe. How can i check if its the waste gate and way to fix it??? Tnx guys


you can actuate the waste gate by hand to see if its sticking. other than that you're looking at maybe n75?.. could be a misfire yes, will throw an engine code if so but the bigger question I would handle first is why you are over boosting.


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## bodya2004 (Feb 21, 2009)

how do i do the wg check


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## murTTer (Jun 27, 2009)

the adjustable linkage that goes to it, you can actuate it by hand.


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## Marcus_Aurelius (Mar 1, 2012)

bodya2004 said:


> how do i do the wg check


Actually, you pressurize the vaccum source going to the actuator. The internal wastegate flap will move as soon as the spring pressure is exceeded. Check for full actuation ( pressurized ) and full return ( pressure off ).


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## Converted2VW (Apr 8, 2009)

Interesting...my car is doing the same thing.

I've checked the vacuum system, the n75, n249, n112, dv, boost leaks, they are all good.
Wastegate or coil packs / plugs are the only thing I haven't checked yet.

And I was using unitronic stg2

We are on the same boat my friend


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## bodya2004 (Feb 21, 2009)

i fixed the stuttering but still over boosting my coils was going under high boost. but dono about over boosting still spikes over 25 scary:banghead:


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## Converted2VW (Apr 8, 2009)

bodya2004 said:


> i fixed the stuttering but still over boosting my coils was going under high boost. but dono about over boosting still spikes over 25 scary:banghead:


How did you fix the stuttering?


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## bodya2004 (Feb 21, 2009)

as i said it was my coil going under high boost


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## 1fast2liter (Apr 4, 2005)

i wouldnt worry if it were really over boosting you would be throwing codes.. i run a apr 93 tune and i spike as high as 22.


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## bodya2004 (Feb 21, 2009)

22 psi is not high at all i spike like 28 i want to run steady 23psi


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## 1fast2liter (Apr 4, 2005)

as far as i know with any tune including stock you will spike and taper off to redline.. it isnt gonna hurt you any. if it was hurting you or you were running lean or what not it wold throw a code or go into limp mode.....


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## EvilVento2.oT (Dec 1, 2003)

bodya2004 said:


> 22 psi is not high at all i spike like 28 i want to run steady 23psi


 Frankenturbo look it up !! a stock ko3 is not gonna do that , or a 225 ko4 for that matter ( at least from what i have scene) 
http://www.youtube.com/watch?v=SNecJgChYCs&feature=related 


www.frankenturbo.com


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## bodya2004 (Feb 21, 2009)

EvilVento2.oT said:


> Frankenturbo look it up !! a stock ko3 is not gonna do that , or a 225 ko4 for that matter ( at least from what i have scene)
> http://www.youtube.com/watch?v=SNecJgChYCs&feature=related
> 
> 
> www.frankenturbo.com


 Well im just saying what is going on with my tt it looks to be a stock ko4 but as i said i spike over 25 every time and then tappers to like 23


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## Marcus_Aurelius (Mar 1, 2012)

EvilVento2.oT said:


> a stock ko3 is not gonna do that , or a 225 ko4 for that matter ( at least from what i have scene)


 Not going to do what?


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## EvilVento2.oT (Dec 1, 2003)

Whoops wrong thread


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