Golf 3 TDI: Help Needed!

Hello!

I'm having a problem. My car won't start. It's been in a VAG workshop since May 2nd, 2003. The mechanic diagnosed that the engine control unit (ECU) is faulty. A new one would cost approximately 850 euros plus tax. Because my budget is very limited, I bought a used one. It was then installed at VW. The mechanic tried to adjust it and reprogram the keys, but unfortunately, it didn't work.

My car:
Volkswagen Golf 3 TDI, 90 horsepower.
Manufactured in 1996.
MKB 1Z
Climatronic.
Cruise control.
Immobilizer.
ABS.
Driver and passenger airbag.
Power windows, front only.
Manual transmission.


Old ECU: No pre-glow, starter motor turns, engine does not start.
Bosch 0 281 001 421/422
VW 028 906 021 BF


New starter motor: Pre-glow, starter engages, engine starts and makes approximately 10 independent revolutions, then shuts off.
Bosch 0 281 001 308/309
VW 028 906 021 AF


Best regards,
Andi


P.S.: I would really appreciate your help. Thank you in advance!

Based on the error description, it sounds like there might be a problem with the immobilizer (in the new control unit).

Best regards, D.

Hello Andreas,
The AF is a downgrade. It's the last generation of 8-bit engine control units (ECUs) (MSA12) that was used in the Golf. Your old ECU (the BF) is already the 16-bit successor, the MSA15. Both have a Wastegate Flap System (WFS), and they are also pin-compatible (the 021GG replaces both older versions).
I've posted about the procedure needed to configure the WFS before -> use the search function (if you can't find it -> email me).

Best regards, Rudi.

Hello Andreas,
Regarding your error description (I forgot):
This briefly starts and then turns off is} the unadjusted.
WFS. That old STG seems to be a bit crazy.
Have you ever taken it apart and looked to see if anything looks burnt?
Was ist der Fehlercode, and if it's even possible to read it anymore?
(Would you like to establish a connection to the control unit?)

Best regards, Rudi.