CFCA primary turbo not spinning at idle

[johnp1982]

Hello, my CFCA bi turbo primary turbo does not make boost. Is the actuator for this smaller turbo (or is it the bypass actuator?) supposed to operate at idle? Mine does. This is the electrical and vacuum combined actuator, NOT the actuator for the secondary lower larger turbo.
I have removed the aluminium intake section off the turbo to get to the compressor wheel and can turn the compressor wheel by hand, so it is not seized.
Have had engine idling in this state and the compressor wheel does not spin at all.
Any ideas what could be wrong?
Thanks
John

 

[DXX]

Have you checked the axial float on the rotor?

 

[johnp1982]

Have you checked the axial float on the rotor?

Yes. Do you know if the rod should operate or not at idle? Want to make sure the vac lines are correct. and to check every thing before i take the turbo off the motor.

 

[DXX]

VIP Membership gets you access to many technical doc’s.
CFCA specific bi-turbo info’;

 

[johnp1982]

Thanks for that. VERY informative. Seems the control flap is open and high pressure turbo has no exhaust gas path.
What I am confused on is drawing shows x1 N75 valves and x1 changeover valve.
I have x2 N75 valves and x1 changeover.
Any ideas as to this?

 

[johnp1982]

Thanks for that. VERY informative. Seems the control flap is open and high pressure turbo has no exhaust gas path.
What I am confused on is drawing shows x1 N75 valves and x1 changeover valve.
I have x2 N75 valves and x1 changeover.
Any ideas as to this?

Ahhh, forget re the x2 n75 valves, got it sorted in my head.

 

[johnp1982]

Yes. Do you know if the rod should operate or not at idle? Want to make sure the vac lines are correct. and to check every thing before i take the turbo off the motor.

Got turbo off and out
High pressure turbo shaft snapped on exhaust side.
Sooo had spare good turbo, but low pressure turbo actuator vacuum diaphram does not hold vacuum. Swapped one from broken turbo.
How do I adjust it properly?
Have vcds.
Thanks in advance.

 

[mmi]

How do I adjust it properly?

Workshop manual has the procedure.

CAAC CAAB CAAC CFCA Diesel Engine workshop manual

3 Feb 2023

CAAC CAAB CAAC CFCA

• Loz
• caaa engine caab engine caac engine cfca engine manual
• VW Manuals

 

[DXX]

High pressure turbo shaft snapped on exhaust side.

Have you determined why it snapped? Lubrication failure, overspeed (mapped)….
Simply replacing like for like may not be the whole solution.

 

[johnp1982]

Have you determined why it snapped? Lubrication failure, overspeed (mapped)….
Simply replacing like for like may not be the whole solution.

No. Do not know why it snapped. Not mapped, engine has good oil pressure. Any ideas what else I should check?