+25 lambda correction in 5K+ revs, Help!

[petelking]

Hi

I'm getting a strange issue with my custom tune and was wondering if someone might help get to the bottom of this.

This issue comes and goes, car will run perfectly one day and then run badly on the next day.

At the beginning I thought it was my Neuspeed induction kit and when I removed it everything seemed to be O.K but then it started happening again.

If you look at the lambda regulation where it's marked in red you will see the ECU adds 25%+ fuel at some point but for no apparent reason.

this only happens in 5K+ Revs.

My setup is:

- Stock K03 Turbo
- Labonte Motorsport WM Injection stage 1, MAP based set to go off at 0.8 Bar
- Stock HPFP
- 3" downpipe with no cat converter

here are 2 log outputs, one is perfect and the other is bad:


Perfect:

BAD:

Did anyone ever notice a similar issue?

Pelase help.

Thanks.

 

[Viking445]

Well since its only happening in #4 i'd check the Coil Pack and Spark Plug.

Also You need to do a proper log. One single pull in 4th gear from 2000rpm to redline.

 

[petelking]

Thanks a lot for your reply.

Car has new plugs, coil packs and cam follower as that was my initial guess but nothing was solved after the change

The same happens when I do 4th 1500RPM to 6000RPM

The #4 cylinder misfire is not the issue and is not supposed to give out such a huge lambda correction.

I'm not referring to the misfire at all, I'm talking about the huge lambda regulation that happens, check out the lambda regulator column and you will see that most of the time I have too much fuel and the lambda is requesting less fuel but at one point between 5000 and 5700 RPM the lambda correction turns around and starts adding +24.2% fuel, this triggers an emergency code and drops boost.

Any clues as to what it can be?

I going to fit an APR HPFP today and set the rail pressure to 120 (Currently 110) but if that doesn't work I'm in trouble.

 

[Viking445]

Any particular reason you didn't get a Tune done by a company? Like BlueFin, APR, REVO, etc?

My only guess about the regulation is maybe your O2 sensor?

 

[petelking]

Thanks for your reply

I like to know what's going on with my car and not put my blind trust in some company.

Custom tunes are always more powerful then off the shelf tunes and if you do them right much more reliable.

if the O2 sensor would go out of range I would probably see a fault code in VCDS so I don't think that's the case.

To me it looks more like an out of range MAF reading on maybe a collision or "bug" in the tune but wanted to be sure it's not something mechanical.

 

[petelking]

Just r replaced the Stock pump with APR pump.

Still the same issue.

I also tried some off the shelf upsolute software and it was even worse.

I'm getting a feeling there is something wrong with the motor or fueling system but I replaced just about everything I could think of.

I’m almost about to cry

 

[08 PASSAT TURBO]

never heard of upsolute...got get a APR trial and go from there....custom tunes on ECU's not as complicated as ours are probably good but for this car its not good. ur tuner cant crack the ecu open like the real tuners can...but do what u want...but im willing to bet $ its ur tune

 

[nitroscope8]

You have a boost leak. Very common issue i've been seeing with these cars is a broken mount tab on the intercooler. grab the fans and move hte rad in and out. If there is any play on one side then the intercooler has a hole in it.

Sometimes its not obvious and you cannot hear it. Also sometimes boost pressures may seem OK! However it causes a rich condition because the computer sees boost but it leaks down before it reaches the engine and it injects enough fuel to antisipate boost. So your misfire is prob from this too.

 

[Viking445]

Would Logging the N75 make spotting a leak like that easier?

 

[petelking]

I checked for boost leaks running pressure through the piping between the turbo and the motor, piping and intercooler hold 3 bar of pressure with no leaks.

If you look at the log there is an N75 column there, it hold 97.6% most of the time but when the issue happens it starts dropping

That is more a symptom then a cause as ME9 Ecu’s drop boost if they reach the maximum possible lambda regulation.

Some more Logs from yesterday:

Upsolute Tune:

This might be so bad becuase the actual boost is much higher then spec...

Custom Tune:

Custom Tune with MAF and Rail readings:

 

[Viking445]

These are the logs i just did for my pre/post front mount thread.
I think its your Tune man. These companies you don't trust have been in the VAG Tuning Business a hell of a lot longer than you have. They know what they are doing.

My friendly recommendation is to get your ECU flashed back to stock to get rid of the stuff you have changed and then get a Proper Flash.

 

[petelking]

Thanks for your advice and for uploading your logs, looking at you lambda regulation calmed me down a little my chip is not yet fine tuned, this is just a rough tune to see how high we can go with EGT and boost.

I think my tuner has been around just as long and I've never seen an “off the shelf” tune that runs better than a custom tune.

I've got much more boost then you with in my log and about the same EGT with much lower rail pressure, I also don't have an Induction kit installed.

Bear in mind that I live in Israel, it’s much hotter than 22 degrees in the intake and I still boost more than you.

So for now at least, I’ll stick with custom and try to fix it.

thanks anyway.

Any chance you can upload a log for block 120, I wonder how much calculated torque you get off your tune.

 

[Poko]

Petel,

You can't really compare your tune to his from two main reasons.

the first is that you are using WMI which in your case also acts as "fuel" as well as a cooling agent and therefore of-course you will be able to lower the fuel demand for similar or better results.

also in a custom tune like yours you are willing to tune to "the edge" which means you will have to update your tune frequently based on variants such as weather , fuel quality , Meth conentrations etc.

When any company offer an off the shelf tune , it has to really work in any scenario and any weather and be near flawless , so of-course they will not be able to tune as high as you allow yourself.

it would be interesting if there was a user with a Race fuel file (104 octane) , that would be more of a fair play comparison.

 

[petelking]

Poko

I have a feeling the reason Shaviv "ditched" me today has something to do with "race fuel" :lol:

The issue doesn’t happen all the time and we tested several scenarios with different fuel and meth quality.

Naturally a chip company, especially APR would always do an “on the safe side” tune that will have less power than a custom tune, I’m not trying to compare my car to his, I just explained to him why I didn’t go for an “off the shelf tune”.

Below is a log with the same exact chip where everything is super fine and this was tested during a week in different weather conditions.

This is forth gear from 1880 revs. I marked 2 things, first just to show off Engin load in NM (calculated torque), Second the EGT temp in 6040 revs:

 

[avihaitopor]

on 3080rpm you have 453.8 nm!
calculated hp 316 at 6040rpm

http://www.ross-tech.net/vag-com/examples/Block_120_Tutorial.xls