What is this sensor?
 

I stole this pic from another thread.. but what is the sensor in the lower left? Mine is broken and disconnected.. wondering how it would affect the engine. Mine is a 76' 911s.

http://forums.pelicanparts.com/uploa...1198883808.jpg

Hi, I could not see whatever you were talking about. Label it like the other items labeled, that way we can see what you are talking about. Tony.

http://forums.pelicanparts.com/uploa...1198885362.jpg

The one on the timing chain cover? If so it is basically a temp sensor.

If it is it is not the one for my gauge. So what needs it? My car is missing badly and I just replaced plugs and cables.. rotor and cap on the way.. BUt I just noticed this sensor is broken and the cable is just hanging there with leftover parts.

Its for the fuel injection. It controls the cold start operation. most of them are disconnected I have found for a reason usually they are bad and cause slow cranking or hard start problems this is just from my experience. I doubt it has to do with your rough running concern.

Okay, thanks.. I'll rule that out then.

Thermotime Switch.....
 

JP,

That's a thermotime switch and a critical CIS component for cold starting. The CSV (cold start valve) will only work when properly grounded via this switch. The red/brown wire goes to the big connector and the yellow wire goes to the smaller connector.

If the TTS is disconnected or defective, it could either effect your cold start or flood the manifold with extra fuel.

Tony

Right now my car is doing several things.. when I start it it is hunting like crazy.. as though it has an intake leak. It also doesnt seem to be fireing on all cylinders when I hold the throttle down a bit.. It has a Permatune and I am starting to think its a bad unit.. cap and rotor should be here monday.. once I replace them I am going to really suspect the permatune.. But I better order this sensor too.

EDIT: from a cold start it runs for 30 seconds with a nice idle.. then it starts to drop cylinders.