Mercedes Benz repair: mercedes benz cold start valve, 1989 mercedes 300e, mercedesshop

Question
I have located to cold start injector for my 1989 mercedes 300e, but I cant locate the sensor on the engine that senses the engine temperature.  The car runs fine after it starts.  All of the usual parts have been replaced, plugs, wires, cap and rotor.  A shot of starting fluid gets it going in the morning so I suspect that the sold start valve isn't working properly.  

Answer
Engine temperature sensor is located in intake manifold.
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