round harness connector next to idle control valve
 

There is a round 3 pin connector covered with a rubber cap. Anyone knows what it is used for? O2 sensor break-out?

http://forums.pelicanparts.com/uploa...1647000530.jpg

if you would used search you would find couple of post lower on this page .. this one;-)

https://forums.pelicanparts.com/porsche-911-technical-forum/1114451-engine-930-21-a.html

Thanks! I did search by the way, but that did not work...i probably used the wrong keywords:rolleyes:

O2 sensor connector is on the left side of the engine bay. But O2 does have a similar looking pinout (but not same)

That connector is for the TDC sensor. There is a magnetic sensor on the upper rear of the engine, in between the engine sheetmetal. It detects the set screw in the flywheel.

So the plug pictured has no actual effect on the running condition of the engine. It's only used for finding the position of the set screw at 12 o'clock on the flywheel, when you connect a diagnostic tool that will "read" the sensor

http://forums.pelicanparts.com/uploa...1647014259.jpg

yup it happen to me as well sometimes...Kevin.. explained nicely;-)

Ivan

thanks guys for the feedback, great to experience the invaluable help this forum and it's members offer