2.2HDI 173 overboost

[citroenguy]

Hello
I've got a new issue with my 'ol high miler.

I seems like the waste gater for turbo 2 doesent work, when you "lean in to it" in 3rd gear or full revs on 2nd it boosts with 1.6bar over atmosphere. And shuts off with no fault codes to prevent it blowing up.
Max desired is 1.4 bar..

3/4 vakuum actuators seem to work, "click/clock" noise when vacuum applied and the rod moves. All circuits hold vacuum.

Three of them get vakuum when you snap the thottle, 4th one has constant vacuum. So solenoids sem to work.

This one seem to work

This one is unresponsive and seems to lead to the actuator on the side

Top left one has constant vacuum on idle, VNT?

The "middle" one is possibly faulty, is this one for turbo 2?

(bottom most is to the charge air valve, not a wastegate)


My doc backup Servicebox is very limited on this biturbo system.

Any one got a good vacuum diagram on this engine?

[mickthemaverick]

I can't offer any help here other than to suggest a read through the thread linked below may give you some idea?

viewtopic.php?p=358534#p358534

[citroenguy]

I can't offer any help here other than to suggest a read through the thread linked below may give you some idea?

viewtopic.php?p=358534#p358534

I saw that thread, but it is sadly about the older 133HP single turbo 2.2HDI.

As i look into it more it seems like the middle vacumm actuator on the picture above is on the intake side also.
But it should in my mind be the the wastegates on the "hot side" that ultimately control the boost.
On high load the charge pipes should be open for both turbos.