2.5 TDI V6 AFB Turbo Lag, Logs Included

[albanno]

Hi
I've been having problem solving the turbo lag issues.
My car is Audi A6 2.5 TDI V6 AFB year 2000
I recently replaced all the camshafts. I bought the kit that adamss24 recommended from ebay (Kolbenchmidt). All the belts have been changed. I cleaned everything possible when doing the work. I did the dynamic injection control. The engine works perfectly now. It starts nicely, nice sound. MAF have been changed. Turbo cleaned. N75 changed. All the pipes have been changed. Intercooler cleaned. Almost everything that I could possible think is done.
The problem is that normally the car should start pulling from 1500 rpm but not for me.
I'm posting the logs so you could see better. I already tried adjusting the actuator arms and the stop screw but without results.
So please if you can help me find where the problem is
The log is done 4th gear full throttle
Thank you

MAF log group 003
y6qPhK.jpg

Group 008
RcK1c1.jpg

Turbo log group 011
Daxa9Y.jpg

[PaulF2.5TDi]

It looks like your stop screw needs adjusting.

It's been a while since I played with this so I don't want to say too much as I may get it **** about face, but IIRC shortening rod length increases sensitivity, stop screw is where it kicks in.

Have a search for posts by me, Ametlib, Sjordet and Turbosteve and there were some very good discussions about this in a few threads.

[SOLVED] Lack of power with 2,5tdi AFB - Page 3

2,5 tdi AKE running rough when warm.

AKE woes, VAGCOM IQ querey.

They should keep you busy for a bit!

[albanno]

Thank you PaulF2.5TDI for your quick answer.
I already looked through all those discussions but still I have not been able to find the problem.
If I shorten the rod when I change the gears, when the engine is deccelerating I hear a turbo noise. it's like turbo surge or something. I think there's too much pressure and it goes back through turbo. I also tried adjusting the stop screw. When I go a little too far with the stop screw I feel the engine is choking.
Funny thing is that whatever I do it does never go into limp mode. Two years ago I changed the turbo actuator (wastegate). While trying to adjust it, if I shortened the rod more than needed I had great power but it was too much and limp mode, so I lengthened it and it was great. Without touching anything the problem came itself slowly when one day it was cold outside and while changing the gear I heard that turbo surge. Since then I could never adjust it correctly.

[ametlib]

Hi,
this time I will agree with Matkring, check if the exhaust system/ twin cat's are clogged up, if you find nothing wrong take out the EGR valve and see how the engine performs without it

[albanno]

I already removed the cat from the turbo exhaust exit and nothing changed. Same thing, same graph. I cleaned the intake manifold. It was not that dirty as I thought. Cleaned the EGR too. Tried with the EGR valve disconnected, put the metal plate to block it and reduced it to minimum via VAG-COM. Nothing...

[ametlib]

Turbo shot ?

[adamss24]

The turbo boost log is actually following the requested pretty well and the N75 is adjusting the duty cycle as needed when turbo gets to 1.2 bar of boost. I would check the MAP sensor first then take a boost log of measuring blocks 03/08 and 11 and post the csv file (raw data) so i can have a look...

[albanno]

Hi adamss24
Here please the log in csv format:

https://www.sendspace.com/file/0cndr8

[bluezie]

The turbo boost log is actually following the requested pretty well and the N75 is adjusting the duty cycle as needed when turbo gets to 1.2 bar of boost. I would check the MAP sensor first then take a boost log of measuring blocks 03/08 and 11 and post the csv file (raw data) so i can have a look...

I read this thread with interest, as my 2.5 AKE is suffering from unsteady boost. The VCDS graph shows viscious sawtoothing of the actual boost around the requested - it jumps from 2500mbar to 1700mbar all the time, although it does settle down a bit in high gears.
I recently dismantled and cleaned the N75. The VNT is very free and snaps quickly fully open and shut using VCDS. The cams were done recently, manifold cleaned, EGR test using VCDS fine. Timing is bang on.
Are the MAP sensors known to give erratic outputs, so the boost cannot follow the requested?
I'm sort of thinking there are only 2 things left, and that's the MAP sensor and the turbo. (it's bound to be the turbo ££££££!!)

[albanno]

Any help guys? Anything that I could check for?