81 911 SC cold start idle oscillation and Mystery Connector

[dugr]

I'm at the beginning of hunting down a cold start idle oscillation issue with my 81 SC. Before I send in my WUR for a rebuild or, look into some aftermarket solutions, I thought I'd start with the basics.

I found this connector on top of the engine cover. After doing a color code lookup, it's telling me that this is for the WUR but, that's not the case with this connector. Any insight regarding this connector would be appreciated.

[Porchdog]

A/c Compressor connector

[Peter Zimmermann]

I think that was not used on the SC (???), but was used in same year production Turbos? Shared wire harness? Maybe heater system blower? Foggy memory, it's been 30+ years since...

[dugr]

On an 81 SC, it's not the A/C compressor, that unit uses a single wire and a spade connector. The heater blower uses 2 wires in a connector but those also are spade. Pete, you're probably right, maybe it's used on the turbos.

[timmy2]

That connector is not used for US cars with Lambda from MY 1980 on.
It is used on all 78/79 and all later ROW engines for the thermo time delay vacuum switch.
Just tape it and forget it.
Porsche used the same engine harness for all SC’s, they just added Lambda control stuff and didn’t use that connector for US/Japan/CDN cars.

[kltarga72]

dugr

I asked for the same question two days ago see thread url

https://forums.pelicanparts.com/porsche-911-technical-forum/1040790-what-does-plug-connect.html

timmy2 comes to the rescue again

Lash


timmy2

[timmy2]

You wouldn’t believe how many times this exact question about this spare connector gets asked annually...

[mike sampsel]

I just plugged mine in yesterday as I installed my CIS. It’s used on the ‘78 on the “card” which has a hose or two. One hose goes to the WUR, I had to pull off the hose on the WUR so I could bolt it down. Then the hose goes back on. These are sure stout hoses in great shape after 41 years!

[boyt911sc]

Originally Posted by dugr

I'm at the beginning of hunting down a cold start idle oscillation issue with my 81 SC. Before I send in my WUR for a rebuild or, look into some aftermarket solutions, I thought I'd start with the basics.

I found this connector on top of the engine cover. After doing a color code lookup, it's telling me that this is for the WUR but, that's not the case with this connector. Any insight regarding this connector would be appreciated.

dugr,

First identify if your car is a US spec or a ROW spec. What is the Bosch ID number on the WUR? What is the heater resistance (Ohms) reading of the WUR when the engine is cold? Keep us posted.

Tony

[dugr]

Originally Posted by mike sampsel

I just plugged mine in yesterday as I installed my CIS. It’s used on the ‘78 on the “card” which has a hose or two. One hose goes to the WUR, I had to pull off the hose on the WUR so I could bolt it down. Then the hose goes back on. These are sure stout hoses in great shape after 41 years!

Timmy2, Thanks for solving my mystery.