VTG connection rod - range of movement?
Hy, I'm a new member of this forum, living in Germany, Munich area... as many others seeking for information and help - driving an Alfa 147 16V JTD (103kW) 2003 model.
I'm having the "common" problem with too high boost pressure (P1235 or P0238) since a longer time: In 5th and 6th gear, when accelerating strongly or at above of approx 3000 rev. MCSF appears, and switching to safe mode. Near this operation conditions, there's the sound of compressed air escaping somewhere.
I changed pressure sensor in intake manifold as well as the VTG selenoid - both with 2 weeks success, then the same fault reoccured. (I suppose that this is an side-effect of the "self-learning" capabilities of the ECU, hiding the real problems for a while)
VTG mechanism seems to be OK, the connecting rod moves approx. 10 mm down towards the vacuum-manifold when starting.
But I'm not sure, if this is the total range of operation. Maybe it is not opening completely, so the turbo will deliver to much pressure at higher revs.
Before I start to disassemble the turbocharger for checking / cleaning the vanes & mechanism, there's my question:
Can anyone please give me information how many millimeters the VTG connecting rod moves from fully open to maximum closed position? Maybe someone has measured this on his car by pushing the rod down manually?
Many thanks in advance & Greetings