Fuel Reagulation

[dylant]

on my 124 '88 there is a green switch that screws into the engine right by the top closest the blower motor, another one further down which is the engine temp. The green switch controls the fuel injection at different tempretures, but one pin has melted off, does someone know how this switch should work, does it hamper engine performance? Becuase I took the last remaining pin off and the car would pull off, just stalled!

[nglitz]

This "green switch" is the coolant temperature sensor for the fuel injection and the ignition module. It's actually two sensors in parallel. There is a resistance from each pin to ground, that varies with coolant temperature. It's quite important to the fuel injection, as you discovered. New sensors are readily available. And highly recommended.

The other two similar looking sensors run the dashboard gauge (single pin) and the electric fans (four pin).

[dylant]

I got the part from mercedes dealership, it was a bit pricy but worth it I think. The car seems a little smoother and actually a marginally quicker. So yes another problem solved! thank you for your feedback!