I will keep you updated as soon as I have news.

No the opposite:
The switch will work as expected when you swap the vacuum line to the manifold and te vacuum cap.

And above sn 30699 lack power below 4100RPM.

I found it in my old thread.

http://www.volvo850forum.nl/index.php/t ... 565.0.html
Google translate translates Dutch well.

Below sn 30699 lack power above 4100RPM

Thanks. I think i have written down when Volvo changed the way the manifold is being controlled. In the very first 20V's the solenoid that controls te VVIS manifold has been connected in a different way. My circuit will work as expected when the vacuum line to the manifold and the vacuum cover are s...

@jantt: What is the serial number of your car?

The very first 850's had exactly the opposite problem: They lacked power in high revs. And indeed I am still willing do design a new series. Microcontroller based, because the analog chip I used is not being produced anymore. Right now we have 3 guys interested: DHLLR27 Jantt Triton (volvo850forum.n...

Hello ;) For some reason I missed a lot of messages from this site. My apologies for my late response. The chip I used in the "Yitsbox" is not being produced anymore. But it seems that there are still people interested in this "Yitsbox" . With an amount of 10 to 20 interested peo...

The chip I used is not being produced anymore.

But it seems that there are still people interested in this "Yitsbox" .

With an amount of 10 to 20 interested people, I can make a new, microcontroller based version.

Hi Mrkleinowa,

They are available again.
Yitsbox

Kind regards,

Yits.