thermo time switch

[pete380]

I have an 85 380sl that takes a long time to come down to the rpms it should be at when warmed up (750). The car idles at 1000 rpms for as much as 45 miniutes. Sometimes it goes back up to 1000 while the car is still warm. I have checked the thermo time switch and it reads 220 ohms whether it is cold or warm. I am planning on replacing it and was wondering if anyone had any other ideas. Could it be the WUR?
Thanks

[abiby]

IIRC the thermo time switch only controls the cold start injector.

I think you'd do better to look at the thermostat switch which measures engine temperature and connects to the idle control unit.