Calling all CIS experts

[Gunter]

Like Paul says: Open the top line and peek inside. There is a tiny screen that can be clogged.
The mix adjust screw is between the FD and Air Sensor Body; look for a small hole.
You'll need a LONG 3 mm Allen; insert carefully to find the hex in the adjust screw.
Mixture is adjusted by playing with the large fast idle screw and the mix adjust screw; you may have to do this several times for fine-tuning.
The WUR can be made adjustable by drilling and tapping into the plug; there is a thread about this.

Modified my WUR

[jonbot]

Hey guys thanks for the advice. I'll take a look at the screen in the WUR this weekend. I haven't had a lot of time lately with school and all, but the first chance I get I'll take a look and report my findings. Thanks again.

[jonbot]

An update is in order, seeing as how I'm not the only one that is/was struggling with surging issues in my '79SC.

I had tried everything short of replacing the fuel distributor. I couldn't get the thing to stop surging. All new rubber hoses, gaskets, WUR adjusted, ignition distributor rebuilt, fuel distributor rebuilt, new injectors, local porsche mechanics stumped, you get the picture. Even though the surge was greatly reduced, there was still a little bit I could feel. One shop even said "that's just the way they are"...Well, I didn't give up, and it payed off.....

One day, a ray of sunlight beamed down from the heavens, when I stopped in to visit a buddy of mine, a local Mercedes guru named Tony. I wasn't even there to talk about the problem, just to say hi, but somehow, we got on the subject. He suggested I try pulling and plugging the vacuum lines to my EGR valve.....lol that did it!

All this time, and it was that friggin' EGR On the bright side, in the process, I've discovered how everything on the CIS fuel system works, soup to nuts, and I discovered a timing issue I was having, as the timing mark would jump around at idle, and off-idle operation, added to that, the vacuum advance was frozen up and not working at all, so rebuilding the ignition distributor did fix half the problem, but plugging the lines to the EGR fixed the other half.

I can officially say this problem has been solved and mark it off the list!

Anyways, hope this will help someone someday!

[Paulporsche]

Excellent!

And another piece gets added to solving the CIS "puzzle".

[jonbot]

Originally Posted by Paulporsche

Excellent!

And another piece gets added to solving the CIS "puzzle".

Exactly Paul

All in all, I want to thank you Paulporsche, Gunter, Boyt911SC, mca, SC-targa, wcc, Souk, 72911, for helping me with this matter. If there was anyone else I forgot to mention, I apologize, you deserve credit as well. You all weren't obligated to spend the time you did helping me with it, but you did it anyways, and I'm truly grateful. I just hope one day I can return the favor.

Jon