Limp mode. Overboost situation. AJM tdi. audi B5

Hi all.


Been having a problem with an overboost situation on my AJM tdi 85kw engine in an audi b5.
When I give it a bit more gas or reach around 3000rpm, It goes into limp mode.
When restart, no problem again.
So I have read a lot about it and thought I narrowed it down to a faulty n75.
Got a new one. Didnt fix the problem.
Meantime I replaced a lot of vacuum lines. Didnt help. Cleaned egr valve and pipes. didnt help.

Now I came across this list of posibilities here and saw one that might fit.


While working on the car, I leaned on the firewall, where the battery is,

on the big hose coming from the brake booster.

Which goes through some big rubber through the firewall. And it did sssssssshh.
I noticed if I push/pull/move the hoses on either side or the rubber itself, it releases the vacuum.

Now I also had the brake pedal issue once.

The braked felt like the car was turned off. The vacuum issues started around that same time.
So could it be this rubber? Or hose?


Thanks

I greased the pipes and put them back in the rubber. They came out of the rubber way to easy for my taste.. Anyway now they leak a lot less easy. Basicly only the inside one leakes when pushed hard. No more limp mode on the road too. But who knows on the way back ;-)

On the way back I pushed it a bit up hill and in 3rd and 4th over 3000rpm. No limp mode yet. Lets see how it goes over time.

No limp mode yet and overtook some cars with nice speed. But now I have battery charge issue Full of suprises this car

This hack with the grease worked for a while, till it gummed up and on long boost situations caused the same problem again.
I got a new part at Audi. Not even 10 euros and the boost is back to stay
The new part actually has smaller holes than the old.
So fixed!