N75 valve issue

**Tatersalad** · 26-05-2015,10:52 AM

Can anyone tell me or show me which hose goes where on the N75. I have a feeling someone messed with it and messed up the vacuum hoses position.

I also run a test using VCDS Lite and the N75 duty cycle stays at 15% no matter what revs

**Tatersalad** · 26-05-2015,01:19 PM

I have inserted a few pictures. 1 of the VCscope mostly at idle but also revved up as you can see.

A pic of the N75 with hoses attached as follows
RED - to EGR
GREEN - to turbo
YELLOW - to the outside world
BLUE - Disappears into passenger side wing
Is this the right setup?

Next picture:
A hose with a screw in it???

Any help on all these would be much appreciated

SAM_1222.jpg SAM_1223.jpg vcscope.jpg

**Doctle Odd** · 26-05-2015,02:06 PM

Do you have a vacuum reservoir? Black plastic ball about the size of a cricket ball? That's maybe where the blanked hose went to

**Tatersalad** · 26-05-2015,02:26 PM

Haven't spotted a vacuum reservoir anywhere.

**abby1** · 26-05-2015,09:10 PM

try passenger side front wing behind wheel arch cover

**Tatersalad** · 26-05-2015,09:47 PM

okay, but why would the other end have a screw in it?

**abby1** · 26-05-2015,10:15 PM

to keep a vacuum check audi part num 443131541

**Martynas26** · 28-05-2015,08:53 PM

I think egr is blanked thats is easy way disconect egr vacuum line and put the screw so u lose no vaccum and egr is not opening. Check or egr have vaccum line attached??

**Tatersalad** · 28-05-2015,09:02 PM

EGR has the vacuum line attached.
There is good vacuum from the line that goes into the N75, there is just no vacuum from the lines that come out and run to the wastegate actuator and the EGR. The grey plug on the N75 gives 12V from the red/white wire when ignition is on.

When I put the vacuum line that goes into the N75 directly on the actuator, the lever moves up in a nice and smooth motion.
So either I have a vacuum leak somewhere ( I have tried several times to find this without success) or the N75 is faulty ( I have opened up both valves and everything inside moves freely) but seeing the other codes it could also be a short in the wiring loom or a faulty ECU.

Think I should call out an auto electrician.........