09 a4 2.0t quattro

Hello Everyone,


First post and I come seeking help on my tuning journey.


Background up front. I'll try to be brief but also informative. I have tuned one other car before, a chevy blazer (turbocharged by me) not using HP tuners.

current vehicle is a 09 Audi A4 2.0T QUATTRO. 250K miles. (Yup, that's right) had new turbo, pistons and rings (among other things from Audi at 80k due to buring oil and the class action lawsuit on that topic)

Major maintenance within the last 5k miles:

New timing chain and guides (febi)
New spark plugs NGK iridium (1 heat range colder)
New low pressure fuel pump (Bosch)
Upgraded high pressure fuel pump (034)
Cam follower
Motor mounts
Serpentine belt
Tensioner
Idler pulley
Maf (Hitachi)
New map
High pressure fuel sensor (bosch)
Pcv / oil separator and all new lines (Uro)
K04 turbo (brand new turbo)
Every single line, seal and gasket going to the turbo is brand new

New seals
valve cover
Vacuum pump
Upper/lower timing chain cover
Intake manifold
Throttle body
Injectors

I am leaving some things off but I think that is most of the major things. The coil packs are also upgraded R8 coils and relatively new, as are the injectors.

Sorry for the long history, but I am trying to give anyone willing to share some advice at least some of the story to work with.

I got a custom tune, but I have been having issues and the guy who tuned it has become unresponsive. I am having a significant drivability problem with what feels like a hesitation, stumble. This usually happens around 4k RPM and can be quite severe. Feels like the engine is going to drop out of the car or I slammed the breaks all of the sudden. It is also brief. So, it happens fast most times and then it's gone, making it extremely difficult to capture on a log. Rarely it will result in a few rapid ? spasms for lack of a better term, with the same behavior. I have a log file and the thing that I have notice consistently is an overboost condition whenever these events take place. I have checked the wastegate preload (it was off on the new turbo from the factory) I have set it correctly and it did help the issue. I also replaced the n75 valve with a new OE unit as the new one on the new turbo was also defective. That also helped, but it has not solved the issue completely. I think the rest of the issue lies with the tune. I have been trying to read other posts and get an idea what is going on but I would love to get some input from people on here that know more than me.



Sorry for the novel and thanks up front for any help you guys can offer.

i have a 09 a4 148,000 miles brand new turbo same exact thing happend car was throwing underboost codes and camshaft sensor codes / headhaskets fixed new coolant lines new water pump new oil sensor, new camshaft sensor and i still have oil light but engine runs fine if i clear code b4 the engine cuts

Contact me if you are still having the same issue

ok, back again. Still working on this issue, but I don't have a ton of free time so I can only get on here every once in a while.

first photo is probably the best capture I have of the issue, surging and then a big sudden drop in power/ rpm.

second photo shows the over boost condition that I think is probably primarily responsible for most of the problems.
I have tried to lower the values in the torque to load and optimum engine torque table around the 4000 RPM sections as well as the maximum desired load. I don't know if this is at all the right things to be changing, so if someone reading this knows more than me please let me know if I am going down the wrong path.

hopefully someone here can help offer some more insight in addition to the reading a research I have done here and other places.

Thanks again for any help,

Attachment 129261
Attachment 129262

i had a similiar issue for a while until i changed plugs and coils. it was the plugs for me . the jolts were so hard i thought it was the brakes then tranny , couldnt see much on a log . it turned out 1 spark plug was missing the inner ceramic sleeve. only happened during wot at high rpms

the turbo boost pressure is more high for CMD boost ....

Quote:

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Originally Posted by noluckhere

i had a similiar issue for a while until i changed plugs and coils. it was the plugs for me . the jolts were so hard i thought it was the brakes then tranny , couldnt see much on a log . it turned out 1 spark plug was missing the inner ceramic sleeve. only happened during wot at high rpms

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Thanks for the reply. Like I said I changed the plugs and coils. Also it runs great at high RPM's just exactly at 4,000 like clock work it has an issue. If it were the plugs or coils I would expect it to happen randomly at different rpms and conditions. Thank you for the insight though.

Quote:

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Originally Posted by Fnetotuner

the turbo boost pressure is more high for CMD boost ....

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I dont understand want you mean, Can you explain a little bit more?

Hello all, I have continued to work on this in the background, and I have made some progress. I have also managed to finally get a clean datalog that I believe shows the issues I am having.

surging issue
Timestamp
7:03
7:05:30
7:07 (little one)


EPC Light, Over Boost Code
7:07:48
7:07:42
7:09:12
7:09:36
7:10
7:10:24

As you can see, both issues happened quite a few times back to back. For what its worth , the issues seem to be much more prevalent in cold weather when the vehicle is also cold. The weather has gotten fairly cold here lately in Colorado and is making the problems worse.

Hopefully someone on here can help point me to the settings or tables that may be causing my issues, and perhaps even help me understand what changes need to be made.

Thanks for looking.

Attachment 140663
Attachment 140664

Quote:

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Originally Posted by zygoat

Hello all, I have continued to work on this in the background, and I have made some progress. I have also managed to finally get a clean datalog that I believe shows the issues I am having.

surging issue
Timestamp
7:03
7:05:30
7:07 (little one)


EPC Light, Over Boost Code
7:07:48
7:07:42
7:09:12
7:09:36
7:10
7:10:24

As you can see, both issues happened quite a few times back to back. For what its worth , the issues seem to be much more prevalent in cold weather when the vehicle is also cold. The weather has gotten fairly cold here lately in Colorado and is making the problems worse.

Hopefully someone on here can help point me to the settings or tables that may be causing my issues, and perhaps even help me understand what changes need to be made.

Thanks for looking.

Attachment 140663
Attachment 140664

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I have found when tuning all my turbo cars, that I change the spark plugs to a cooler plug NGK6 to NGK7 ECT, more importantly close the spark plug gap down to stop the extra boost from stopping the arc.
The Volvos I have tuned have a stock size of 32 thou and I drop them to 25 thou to stop the issue you are having.

Hey Drill, Thanks for the reply. I am running 1 heat range colder plugs. NGK BKR8EIX, which seem to be the defacto standard just about everywhere I look. I have also gapped them down to .023" if memory serves. (I think stock plugs in the mid 30's ~.035") Most of the info online says to gap them .024-.026" I went just on the low side because I was worried that the gap may have been part of the problem. New plugs and gap have not made a difference. I also have new R8 coilpacks.

If you have any other suggestions I'm all ears.

Quote:

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Originally Posted by zygoat

Hey Drill, Thanks for the reply. I am running 1 heat range colder plugs. NGK BKR8EIX, which seem to be the defacto standard just about everywhere I look. I have also gapped them down to .023" if memory serves. (I think stock plugs in the mid 30's ~.035") Most of the info online says to gap them .024-.026" I went just on the low side because I was worried that the gap may have been part of the problem. New plugs and gap have not made a difference. I also have new R8 coilpacks.

If you have any other suggestions I'm all ears.

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Remove the iridiums and just get a set of stock cheapo BKR8E copper plugs and try it again at the smaller gap..

Are you still getting EPC light after changing plugs and gaps?