RS2 Boost problem

[Tcheri]

Hello,

I have a boost problem on my RS2 since I bought it. I do not have any history, so I do not know when the problem occurs,

My problem is :

- boost pressure, measured at the ECU, max 0.4 bar

Test done :

- New N75 (even 2x), test from ECU ok (actuators test) -> wiring shoud be OK
- No error message on the monotronic (using VAG-COM)
- If the N75 is removed, the turbo/wastegate is giving boost -> it's not a problem of leak in the air circuit. Pressure measure at ECU is also correct in that case (>1.5 bar)

I've send the monotronic for test in UK, and they said it's ok. I've bought a spare ECU, same issue. Anyway, I am not 100% sure that ECU are ok. I should test one in another RS2, something I didn't did (I do not know someone with an RS2).

Any idea ?

Thanks, Thierry

[blux]

Where in Belgium do you live? I'm working on rebuilding an RS2. I don't have a running car but have all parts to swap and test on yours.

[Tcheri]

Where in Belgium do you live? I'm working on rebuilding an RS2. I don't have a running car but have all parts to swap and test on yours.

That could be great. I am living in Thuin, 30 km south Charleroi

[twoqu]

http://forums.quattroworld.com/s4s6/msgs/22584.phtml

[Tcheri]

http://forums.quattroworld.com/s4s6/msgs/22584.phtml

Hi Twoqu, that sound interesting ! But is it normal that I do not have any fault code if it's a F76 problem ?

[twoqu]

Yep!
Its a well documented fault on here and costs nothing to prove or disprove. Simply remove the wiring connector from the MFTS and see if the fault clears. You will lose the temperature gauge during this procedure but it does not effect anything else.
The fact you have just 0.4 bar of boost indicates the bost control is disabled leaving only the mechanical boost control of the wastegate spring. The WGFV is effectively being disabled electrically rather than having a fault.
The Motronic does not unfortunately log such faults.
Cannot be certain it is the problem but its worth eliminating it by doing as suggested above.
Good Luck!

[Tcheri]

Yep!
Its a well documented fault on here and costs nothing to prove or disprove. Simply remove the wiring connector from the MFTS and see if the fault clears. You will lose the temperature gauge during this procedure but it does not effect anything else.
The fact you have just 0.4 bar of boost indicates the bost control is disabled leaving only the mechanical boost control of the wastegate spring. The WGFV is effectively being disabled electrically rather than having a fault.
The Motronic does not unfortunately log such faults.
Cannot be certain it is the problem but its worth eliminating it by doing as suggested above.
Good Luck!

Thanks for your help, it was exactly that ! Really happy :-)

[twoqu]

Excellent! Thats the last cheap and easy fix you are likely to have!