CIS Issue solved
 

Thanks everyone for the CIS troubleshooting, and advice on the location of the darn mixture screw. But in the end, I had my 80 SC towed to the mechanic to solve my issue, here were the symptoms and the solution: (for the archives)

Rough running, idle hunting, idle not backing off during high RPM's, popping from exhaust, rich running smell.

Solution was replace the o-rings for the fuel injectors, one two were cracked and causing a huge vacuum leak. I personally never thought to check for a leak at that location, but now that I think about it I should have.

Also one potentially bad fuel injector with a drip.

Scott

Thank's for the info.

Many Porsche owners take for granted the O-rings and the mechanical F-Injectors . We tend to forget the small Items

VicSmileWavy

I know I was loosing my mind on this, I spent almost all of Saturday morning going through the archives here. I about lost it! That being the main reason I had it towed to the mech, and I'm glad I did, he told me I could have had a "car-b-que" on my hands had I driven it to him.

Thanks for letting us know. It appears to me that a few things keep popping up in the threads: Vacuum leaks, Decel Valve and WUR malfunction seem to be @ the heart of most of these CIS problems, while an incorrect mixture for the season seems to come be the most common adjustable problem.

Scott,

Congrats!!! I could tell from your post you were ready to rip your car apart. Glad you fix it (or at least the mechanic did). Now you can get back on the road!!!