Boost Issues with VAG Logs Graphed

[Cumulonimbus]

I have an 2008 GTI, APR Stage1 with a drop in filter - owned since new so I know there's nothing wacky that's been done by prior owners

I have been having some crazy boost issues lately, unable to spool past 3-5psi, then if you tap the throttle a few times the boost comes back or spikes like crazy to 26+ psi. Bad gas mileage, waving boost from 8-15-8-15psi ETC

I unplugged the MAF and things seemed to be much more controlled and smooth, and my fuel mileage went back up!

So I bought a new MAF and took some logs....

Things replaced;
Rev D DV
PCV
Coilpacks
Plugs
Filter
Cam Follower

After changing the MAF things were still a bit wonky but the ECU seemed to re-learn things after a few pulls and everything was back to normal! I think.....

Can you guys check these logs and let me know what you think?

Heres a log in stock mode while I believe the car was 'relearning' after the new MAF - full throttle, spike in boost followed by huge boost loss, to gradual increase - consistent with the issues prior to MAF replacement.

Heres a stock mode log when I believe the ECU had re-learned and things seemed to be holding good...

Heres a log in Stage 1 91oct - Notice there is a weird dip around 5300-5500 rpm - this has been an ongoing issue for me since before the crazy boost issue and came up in all 3 logs I ran - any insite on this?!

Any pros out there with some expertise on this? Any other data values I should log? :thumbsup:

 

[vegasGTI]

Your n75 it's dipping where it should be spiking. I would check that immediately.

 

[ToucanLife]

Your n75 it's dipping where it should be spiking. I would check that immediately.

Even in the logs after the ECU has adapted?

 

[vegasGTI]

All of the logs the n75 looks like crap

 

[Cumulonimbus]

All of the logs the n75 looks like crap

Thanks for the help man, just ordered a new N75!

Does anyone have any logs of a properly functioning N75? Or could they explain what it should look like ideally?

Just so I can confirm the issue is fixed when I re-log with the new valve :thumbsup:

 

[vegasGTI]

At 2krpm when you floor it the n75 should spike up to like 95 percent or so and slowy taper down to about 60 percent or so by redline. Your highest duty cycle is around 80 but even that plunges instantly most the times your dipping into 40percent and fluctuating up and down from there.

 

[Cumulonimbus]

Just a heads up for anyone with this issue, new N75 did not fix the issue.

Tried replacing the MAP and that also did not fix the issue.

Figuring the wastegate is stuck / failing now.

 

[The Fed]

I believe APR would have told you what was bad if you sent them logs.

Check their website.

 

[The Fed]

I believe APR would have told you what was bad if you sent them logs.

Check their website.