Boost Cut !

[lostaudi]

Go back and try the other side this time

[lostaudi]

The car is standard only addition is a defi boost gauge.

No chips, no wastegate spring, no chav valve, no mushroom filter.

Standard car


Cheers

[prj]

Okay, is the wastegate cap drilled? Or not?

[lostaudi]

No it's standard as it was when left factory in 1992

Not drilled

I was told to check the N75 as its know to fail.

As I dont have another N75 I used the manual valve as a temp fix

Thanks

[prj]

Yeah, then check N75 and also check all the hoses going to and from the N75 for leaks.
If your car is completely standard, then you should never get 1.5 bar spikes, and it's normal that it instantly cuts boost...

[lostaudi]

I checked all the hoses for splits and leaks all are fine.

On full throttle when it did not cut the boost was surging for 1 bar to 1.5 bar

Will try and find a N75 for testing today

thanks for help

[prj]

Mm, maybe the valve is getting stuck on somehow... or the wastegate is getting stuck for some reason.
Also, verify that the moisture trap is okay on the car on the hose that goes to the ECU.
Check that the hose is not full of oil.
It is also possible (albeit unlikely), that the MAP sensor has failed, usually due to oil ingress into it.

It's better to check the more likely and simple things first.

[lostaudi]

I will check the trap

All three N75 hoses are dry no oil

[Foeglass]

@ PRJ,

My wastegate spring is original the cap however has been touched before, but is now set to 0.6 bar i beleve? . with the N75valve disconnected.

I've just replaced both knock sensors, and took her for an two hour spin. keeps pulling strong mabey even better than before?? haven't had a single boostcut yet...
Had a go against a MKIV R32 on the highway, he kept trying to keep up when the lane was free for me to give it WOT.
The're not really fast cars was quite amazed to see how fast i pulled away from him.. they do sound awesome though!

Gonna use the S2 as my daily driver this week and try and see if this really was my problem? i for one hope it was.

I've got an untouched and 100% original ABY ecu i can try out.

[prj]

@ PRJ,

My wastegate spring is original the cap however has been touched before, but is now set to 0.6 bar i beleve? . with the N75valve disconnected.

Why is your N75 disconnected?
Or you mean for just checking boost level?

Move the screw back up so it's 0.4 at spring pressure. 0.6 is too much unless you have a custom map for it.
Also, check car with vag-com.

[Foeglass]

Vag-com gave me these codes. and i just checked again. the car now has no faultcodes.
And she still runs strong haven't had a single boostcut since monday.

00561 - Mixture Adaptation
00544 - Maximum Boost Pressure Exceeded
00537 - Lambda (Oxygen Sensor) Regulation: Upper Limit

N75 was disconnected only for checking boost level.
I will screw it back up to 0.4 bar tomorrow. see if it makes a difference.
The chip is based on a standard ABY engine.

Thanks for you feedback PRJ!

And Scotty did you made any progress yet?