W124 300CE-24 High Idle Broken TVS/TPS

[maxrobot]

Hi All,


I am the owner of a 89 300CE-24 5-speed with ASR!
Anyway I have the not unfamiliar problem of a high idle, ca. 1000-1200, when in either neutral or park.


This issue is often attributed to a faulty IACV. I have eliminated this as by testing the unit outside the vehicle and when voltage is applied the unit moves to the relevant positions.


Following this I tested whether the IACV was receiving any power which is was/is not.
Next step was to check the throttle position sensor or throttle valve switch. Having followed the KE-Jetronic throttle switch tests, see here https://www.youtube.com/watch?v=s9WjaO61QyI 1, I have found that my TPS sensor is broken, as when moving the throttle the resistance does not change when measuring across pins 1-2 and 2-3 as in the video.


Another thing I have done is check the duty cycle reading which shows 95%. According to this source this is an issue with the micro-switch of throttle linkage.


Now I am stuck what to do. Should I replace the sensor? Is this easy or hard?
Any advice appreciated,
Friedrich