1980 450sl r107 TPS

[mccauleybil]

My new to me 1980 450SL runs great! However I have just realized that the TPS (throttle position sensor) was disconnected. On closer examination, the 3 wires had been frayed and 2 were cut (alternator?). I have repaired the wires, and reconnected the TPS. My question is ... if the car ran nicely without the TPS, what advantage will I notice now that the TPS has been reconnected? Thanks!

[Frank Reiner]

Originally Posted by mccauleybil

My new to me 1980 450SL runs great! However I have just realized that the TPS (throttle position sensor) was disconnected. On closer examination, the 3 wires had been frayed and 2 were cut (alternator?). I have repaired the wires, and reconnected the TPS. My question is ... if the car ran nicely without the TPS, what advantage will I notice now that the TPS has been reconnected? Thanks!

The device, "TPS", is not a position sensor. Rather, it is a throttle valve switch (TVS), in MB terminology. There are two contacts within that sense either Throttle Wide Open, or Throttle Wide Closed, respectively. That information is used by the frequency valve controller to operate in open loop when the throttle is at either extreme.

[mccauleybil]

Thanks Frank for redefining the part's name. In your opinion, what is the consequence of a unattached TVS, versus a attached TVS? Truly, I appreciate your assistance.

[Frank Reiner]

Originally Posted by mccauleybil

Thanks Frank for redefining the part's name. In your opinion, what is the consequence of a unattached TVS, versus a attached TVS? Truly, I appreciate your assistance.

Provided that the frequency valve and its controller are functioning, at full throttle closing those contacts results in a richer mixture, and at closed throttle closing those contacts removes the slightly oscillating mixture situation that occurs when in closed loop.