vtraudt

When cleaning the EGR passage, it struck me later on that the linkage on the TB may be for a 2 stage intake setup? Since I am complaining (among a lot of other things on that car) that it does not make expected power: could it be that the actuator is not opening the 2nd stage?

How can I check? Should it move at a certain RPM (that I can do by just revving the engine in P)?

Other checks to do, symptoms to look for?

Luxus Panzer

you will see the linkage on the back of the I.M. move between 3 and 4k RPM

VAP

Actually its designed to open at 4,100RPM

turbo510

I just checked this on my '96 the other day. A friend watched while I eased the revs to over 4K, he said the actuator pulled the linkage "bigtime"

Lago Blue

The motive force for this actuator is stored vacuum. Common faults may include but perhaps not limited to:

- insufficient stored vacuum due to:
-- disconnected vacuum lines;
-- a defective vacuum reservoir, either heat damaged or cracked hose mounting nipple;

- lack of transmittable vacuum due to:
-- poor quality OEM soft vacuum lines, or
-- kinked or chafed hard vacuum lines;
-- defective actuator diaphram;
-- defective or inoperative vacuum solenoid (N156)

- mechanical linkage disconnected or broken, caution, it is delicate.

see some schematics here:

http://pictureposter.audiworld.com/5...or_website.jpg

https://www.audiworld.com/forums/sho...ghlight=change