Did you made TB adaptation after instaling new ECU?
Thank for the suggestion, i went straight ahead and tried it but sadly it hasn't solved the issue. I have now tested the original ECU again and that still works fine.
What i think i'll try is flashing the exact same BIN that the original ECU has onto the new one and see if it idles properly. So without any of the changes.
Table: KFTVSA - Switch delay time for overrun cut changed.
Table: KFZWMN (Minimum ignition angle) changed.
Scalar: VNMX changed from 20.00 km/h (0x10) to 1.25 km/h (0x01).
Scalar: DNMAXH changed from 200.0 U/min (0x0320) to 50.0 U/min (0x00C8).
Scalar: ITNMXH changed from 655.350 s (0xFFFF) to 0.000 s (0x0000).
Scalar: NMAX changed from 6800.0 RPM (0x6A40) to 3000.0 RPM (0x2EE0).
Scalar: TMOTNMX changed from 80.25 Grad C (0xAB) to -48.00 Grad C (0x00).
Scalar: TNMXH changed from 0.000 s (0x0000) to 655.350 s (0xFFFF).
Scalar: NMAX changed from 3000.0 RPM (0x2EE0) to 3500.0 RPM (0x36B0).
These are all the changes i had made, after which i checksummed it and flashed. Maybe i got something wrong here which causes the very bad idling.
Edit; After some further testing it seems the problems on the new ECU only start when the first lambda starts doing its work.... i haven't changed anything regarding this.