Mystery connectors engine compartment

[jaustinmd]

I recently acquired an '82 911SC that looks and runs great! Today I was installing Pelican's "dual shock kit" for the engine hood (works great!). I installed over on the driver's side of the car. While rummaging around the engine to gain access to the gas shock for the hood, I noticed a wire coming into the engine compartment from the left side that was just laying there beside the valve cover on the left. It was unconnected and has a substantial rubber connector (female). I tied it up with a zip tie (I was going to ask the tech at Eurotech in Knoxville what it was the next time I was in for service) but wondered if anyone could identify it for me with a picture. I also noted that immediately behind where I tied it up, there was a green wire with a male connector!

Can anyone identify either of these? Everything on the car seems to work fine, just a mildly concerning that there are connectors laying around ... unconnected!

Thanks,
John

[K Sykes]

Looks like the O2 sensor to me - is the green wire going through a crumbling brown plastic cylinder? It looks to me like I can see a bit of it near the green wire. You should be able to follow it down to the Cat, wire goes through the engine tin if its the O2 sensor.

[kodioneill]

O2 sensor for sure.

[jaustinmd]

Originally Posted by K Sykes

Looks like the O2 sensor to me - is the green wire going through a crumbling brown plastic cylinder? It looks to me like I can see a bit of it near the green wire. You should be able to follow it down to the Cat, wire goes through the engine tin if its the O2 sensor.

Thanks - yes, the green wire comes out of a brown plastic cylinder - what does that do?
John

[schoward]

Those two things plug into each other (male/female). Oxygen sensor connection. Very common to find them just as they appear here and common to find the male end mangled or crumbling. Many disconnect as they feel car runs better without it connected. I have run mine both ways - connected and disconnected. When disconnected, many set the mixture to a non-spec value (rich) which when you plug the sensor back in could cause the car to do odd things.

Explaining the rest is a long story. Read up here with some searches and talk to a good wrench. If the car is new to you, I would suggest enjoying it and learning about it and get back to this is in due time. You can drive yourself crazy pretty quickly until you learn the ins and outs of the Lambda CIS system.

[James Brown]

check under the passenger seat to see if the brain box is even installed before fixing that plug.

[jaustinmd]

This car has within the last two years had the engine, transmission, and clutch completely rebuilt and drives and runs great! I think that it is good advice to leave well-enough alone for now. In the fall, I'm going to take it in for service to the tech who did all the work and let him go over with me all the "unconnected" things and go from there.
Thanks for all the great info!
John

[javadog]

An '82 will run better and probably get better mileage with the O2 sensor plugged in and everything functioning as it should. Lots of people that don't understand how the system works unplug these "to make it run better" or to "fix" some problem that's related to something else.

Porsche made changes to the CIS system in the 911SC almost every year. It's not enough to understand how a basic CIS system works, you need to also understand all the little changes Porsche made. There were a bunch of them...

JR

[scottrx7tt]

That being my old car. When the 02 sensor was plugged in, it caused the idle to surge. So I just left it unplugged, as do most people with the newer SC cars

[javadog]

Originally Posted by scottrx7tt

So I just left it unplugged, as do most people with the newer SC cars...

... when they choose not to fix the problem that is causing the symptom.

JR