911SC CIS help: what's this sensor?
 

Hi all,

I have a 1982 911SC with some CIS components missing. My car does not have any of the oxygen sensor equipment (sensor, relay, harness, controller).

I removed my CIS to replace all vacuum lines, gaskets, clean the injectors, and fix the wiring. Prior to this my car ran decently well but would idle at 2000 RPM when hot and would run better on cool days than hot days.

There is a sensor on my passenger side timing cover...what is this? You can see it in the lower right hand corner here:
https://c1.staticflickr.com/8/7285/2...91f67a1c_z.jpg

I also have a yellow wire with a blue tracer that came off the CSV (I think it was the CSV). This goes on my starter, right? It was just cut and loose under my CIS...

https://c1.staticflickr.com/8/7396/2...f67994d6_z.jpg

Thanks all!

Pelican Parts - European Automotive Parts and Accessories - Porsche • BMW • Mercedes • Volkswagen • Audi • Saab • Volvo • MINI

Temp switch in the cam chain cover. (click on link above)

I believe that the red and yellow go to the thermotine switch in the drivers side cam chain cover. you can use your multi-meter to verify this. The disconnected should go to the starter.

regards,
al

Thank you! Yes, you are correct - the red and yellow wires seem to go to the thermotime switch. I find it interesting that the yellow/blue wire is not connected to my starter yet my car has absolutely no problems starting. In fact it starts almost as quickly as a modern EFI car. I would have thought the disconnected wire would prevent the CSV from doing its job.

The temp switch on the chain cover should connect to...my oil temperature gauge? If so, that's strange because my gauge seems to work properly.

The temp switch on the chain cover is for the lambda controller.
The yellow blue supplies power at start for the TTS and cold start injector system.
If you live I. A warm place above 20 degrees, the cold start system likely isn't needed.
Or, the system is set up so rich it will start.
Time to test the fuel pressures with a gauge and check the CO to see what is what.

The oil temperature switch located in the passenger side chain case is not the one for your temperature gauge. It is a temperature switch that provides input to your oxygen sensor control unit - I think you said yours had been deleted. When the engine is cold this switch is "closed" the oxygen control unit keeps the system in "open loop", when the engine gets to 59 degrees F the switch opens and the system goes into "closed loop". The Bentley service manual provides very good information on all aspects of the CIS system - it has been very helpful to me in understanding and working on my 82 SC.

Perfect! Thank you for your input everyone. I understand what's going on now. I'll just extend the yellow/blue wire and properly attach it to my starter and ignore the temperature sensor for the lambda system.

I have a set of low-res wiring diagrams for a 1982 SC but was unable to figure this out on my own.

Regarding the mixture: I have no doubt that it was less than ideal. I will set it roughly in my driveway once I get all of my CIS parts back in (hopefully my injectors spray well enough that I don't need new ones) and then get it set professionally.

I may also buy a wideband AFR monitoring system in the near future for fine tuning. It's possible that a rich condition was causing my high RPM surging and high idle but since I had no record of CIS system servicing I wanted to replace every gasket and seal before getting the mixture set. No use setting it up if I have air leaks, right?