Speed Sensor Question-S52 Swap OBD 1

[brads2002]

Hello,

My OBD 1 s52 is down on power and will not pull past 5500 under load. Free revving it will hit the limiter. We have eliminated vanos issues and fuel issues but looking around it seems folks were having this issue due to a speed sensor or ABS issue. Id like to start by confirming my circuit is complete from what i understand is from the dash to the DME? I am not really sure how to trouble shoot this or what wires I am looking for. The DME ends in 413 and it is a non cruise control car. I do have one solid black with a blue line in my harness that doesnt go anywhere. The chassis is a 1991 318is

Thanks for any tips.

[Digitalwave]

Have you pulled the codes? It is likely the VSS (vehicle speed sensor), which is sort of a soft-limp-mode.

If you don't want to diagnose or fix that, it can be deleted in the tune.