Thank You guys!
marracc yes I don't have clamp on that pipe and will put one on it. About the segregator I think to check and clean it but want to collect some more information about turbo cars, because this is my first one with turbo.
aurick86 i will check the waste gate movement.
About graphs, I have made two runs - first at 3 gear , and second at 4 gear. Just not have been sure which is right.
If the test with segregator is reliable i will try it before dismount and clean.

And again BIG thanks for help

Deyan86 said:

Thank You guys!
marracc yes I don't have clamp on that pipe and will put one on it. About the segregator I think to check and clean it but want to collect some more information about turbo cars, because this is my first one with turbo.

aurick86 i will check the waste gate movement.
About graphs, I have made two runs - first at 3 gear , and second at 4 gear. Just not have been sure which is right.
If the test with segregator is reliable i will try it before dismount and clean.

And again BIG thanks for help

Click to expand...

First try with clamp, before dismounting separator. Plastic clips on separator may break when you try to open it, so be careful.... I broke mine while trying to open and clean it, so i bought a new one....

Ok guys i found the problem, but not sure how to repair it.
I'v attached two pictures of the pipe from which when turbo makes some pressure the compressed air goes back before the turbo. I don't know which sensor or valve commands when compressed air goes through this bypass pipe.
When closed this pipe and make a run with MES, it shows higher values of boost, something like 3000 rpm -> 1750 mbar, but also car gives an error P0039 - Turbo vacuum valve.

Hi again. I found that is the turbo diverter solenoid valve. And if it is a electrical controlled valve is there a way to check that the problem is from it?
Thanks!

The hose you plugged up is from the turbo diverter valve.
It's electronically controlled. it's normally closed (no air coming through that hose). it opens up on throttle lift-off or when the ecu detects overboost error states.

Try unplugging it's connector, see if it closes.... if it closes than it's an electric issue(complicated), if it doesn't it's the valve needing replaced.

Ok, I'v make a test. Unplug the connector and there is no difference. The air still goes through the hose when the peddal is pressed and rpms are above 2000 rpm. And even the rpms is low there is a vacuum at the end of the hose. That means the valve is always in open position. I think it is time to dismount the valve and check it visualy or maybe if it is possible even to disassembling it.

Ok, so the valve is gone. The rubber spring that have to push valve in closed position is get soften and valve stays always open. I have ordered new one and hope everything is going to be ok.
I will write after install a new one.
Thanks again!

So here are the result after changing turbo diverter valve.
Car now boost up to 1 Bar. Finally i'v feel the spirit of this car.
aurick86 thanks for every helpful post!!!
I have some other questions now.
This graph is made at 3 gear from 1000rpm.
1.Is not the boost pressure too high? It goes up to 1.5 Bars. Were are the boost pressure sensor located, maybe at the pipe before hose that going to diverter valve?
2. When changing gears at 3000rpm or higher a hear this whistle noise from air going through turbo charger. That mean the compressed air can't goes fast enough through diverter valve. Is that normal or what?
I have some problem with attachment so here it is https://imgur.com/a/j20ClTu

P.S. And one more thing do I have to make Self adaptation and Phonic wheel learn reset after valve changing?

Deyan86
You need to compare "desired boost pressure" with "intake manifold pressure" (which are close enough to each other.)

The "boost pressure" value is the value of the boost before the throttle plate... basically the pipes from turbo to just before intake manifold.

I'd be interested in seeing another graph with desired boost, intake manifold pressure throttle %, and rpm. ("boost pressure" seems a bit to much...maybe throttle isn't 100% opened or there's another problem .... on the wastegate side.. solenoid.. or boost lines... or something there).




Play with the scale..and make the graph as big as possible. (now it's set at 10X).... not sure if you need to select 100x or 1x. Give it a try and make the graph show up wider on the page.

marracc said:

Hi! I just want to confirm situation with boost cut. I had the same problem with my T-jet. Car was producing woooosshh nosie when throttle was fully pressed. Acceleration was poor after woooshh noise. I was thinking that some clamp is loose or something, but it wasnt. After running MES i saw that throttle is closing after boost rises to high. I have changed three way waste gate actuator and problems were solved!
Here is the graph:
http://uploadslika.eu/image/gmXas

I would like to put some tags for people with same problems, because i spend a lot amount of time to find this thread
Tags: boost cut, boost problems, wastegate, waste gate, differential valve, T-jet, tjet, 1.4 T-Jet, turbo noise, pressure converter, 46813571, bad acceleration, poor performace

Click to expand...

Here is graph when three way waste gate actuator was changed, i think it looks ok, any comment is appreciated. I think that graph should look like this when everything is working as it should.