My 89 300E (127K) has recently lost its "choke" when cold. Starts right up and immediately the idle drops to 400 rpm +/- and is very rough. If I hold the accelerator to 1500 rpm for 30 seconds while it warms, it will idle and drive just fine.

I'd like to check my coolant temp sensor but cannot find the resistant specs in my UK version Haynes manual. Can someone please post the specs? I'm assuming this sensor is the culprit and I believe it's the green two lead sensor closest to the firewall on the cyl head. Pls correct me if I'm wrong. FYI....OVP, wires, plugs, dist, rotor, fuel filter, coil, etc., have all been replaced recently.

I also believe there's another sensor (ignition?) located nearby but I've heard that if it fails the car just simply won't run. If you believe that this one is worth testing, please post the specs also (if you have them)....is it the next two prong sensor moving toward the front of the engnie (there's a small one prong sensor in between them)?

Many thanks.