Re-introduction and photos, and CIS question please

[JCFL]

Hello guy,

I have been reading this board for 4 years now. Time to introduce my new to me 1982 911 SC.

I drove a 1984 Carrera for 3 years, until i destroyed it in a crash last summer. I was not hurt but the car was totalled. I spent 6 months shopping in the 1980 to 1989 range, and finally settled on this Chiffon White car.

I bought it in April, in Lake Geneva, WI, at 130,000 miles on odometer, and in reasonably good condition. Drove it 1700 miles home in Eastern Canada (NB) without problem.

I am now spending some time fixing the small items, and I also enjoy driving it. It seems less difficult to drive (read shift) than my 1984, probably because less powerful.

Please see pictures below, with my wife modelling the car for your viewing pleasure.

I have no access at all to CO measuring equipment, and my car is not perfectly tuned (CIS) for air / fuel mixture. I have some black carbon deposit just above muffler, just below bumper. From what I understand, this indicates too rich a mixture, so I turn the dial (using the 3 mm allen key in the hole) about 1/8 of turn counter clockwise.

Now the car was idling more roughly cold, so I figured my adjustment was too far, I therefore went clockwise 1/16 of a turn, which would mean I am at about 1/16 of a turn leaner than before (less fuel, more air). I have adjusted my idle rpm at around 900 . Car performs well, but i still have a black carbon deposit at the back of the car (film layer on rear bumper).

I have read several posts about CIS adjustment, and it seems that without an actual meter, I will have a hard time finding perfect spot in the dial for no carbon deposit (meaning a cleaner burn).

Any suggestion please. As I was saying, car operates well but does produce a film of carbon on the back of the car.

Thank you.

JCFL

[JCFL]

bump for more viewing. Thank you.

[SCWDP911]

dude, I can't believe you let her sit on the car!

Welcome back and nice looking white car.

[OZCarrera3]

Very nice car. Although I do have a thing for white 911's!

I didn't think you could adjust the CIS on later SC's using the mixture screw? A friend of mine has an '81 and this feature does not have this feature (the screw is there, but he has been told it doesn't affect the mixture), but I'm sure other can chime in here.

Just an observation, but the exhaust outlet appears to be very short and close to the bumper. Are you sure its not just discolouring the paint with normal exhaust fumes?

[JCFL]

Thank you guys.

The car is actually chiffon white, kind of closer to beige or off-white if you will.

I wish the black carbon was just discoloration, but it is really a deposit from the fumes of the car. Not a problem short term, but I want to fix it as I am having a major paint maintenance work coming soon (waxing, buffing, the works).

In the 1983 model, there is an adjustment screw accessible on top of the fuel distribution assembly mecanism, for use with a 3 mm allen key. Apart from the black deposit - there is no visible smoke by the way - the car runs very well. Since I have made the mix leaner, I am having some inkling of back fire, but no back fire per se.

I have read some places that there is supposed to be some clicking when you you turn the screw in either directions. In my case, there was no such clicking event with a full quarter turn of the screw. . . .

Thanks for your input.

JCFL

[OZCarrera3]

JCFL, the description of "no clicking" matches the what happens when you adjust this screw in the '81 car I mentioned. In my '76 Carrera 3.0 there is a subtle, but definite click or notchiness when using the adjustment screw. When you do adjust it, there is a noticeable change in the tune of the car. You should be able to wind it back until the car stalls (keeping note of how many turns of course).

[JCFL]

Thank you Sheldon,

What do you mean by wind it back ? Should I go lean CCW until it stalls, and then rich CW the same (or rather till the rpm goes beserk ?), and set it in the middle ?

Not quite clear. And I actuallyu thought that I would not ever do more than one full turn in either direction ?

Thank you.

JCFL

[tomphot]

Very nice - 1 suggestion - paint your lug nuts white - I think it would look great.
I have a silver car with the fuchs painted the same color as the car, it had black nuts, I painted them silver and it really looks good.

[Daviboy]

JCFL take the car to someone who knows what they are doing. My 82 was also out of whack and I fiddled with the adjustment screw to no avail. Oh and there is not click when I turn mine either. Find yourself a good Bosch service centre and have them measure your fuel pressure etc then set up the CIS properly. You wont regret doing this I didn't it is a finicky thing to set up but once it is running right is very reliable.

[psalt]

JCFL,

If your car is a US model with CIS lambda, you can set the mixture using a dwell meter. Everything you need to know can be found by searching this site.

[OZCarrera3]

JCFL, actually I agree with Daviboy, take it to a shop and get them to adjust the mixture against a gas analyser etc. You can 'play' with the adjustment screw and probably get it to run well, but there's little substitute for professional experience and the right tools.

[James Brown]

If you change the setting, the other things will compensate for that to a point. Best to take it to someone who knows. Once "fixed" it should be trouble free for a long time.

[don gilbert]

hello jcfl, clockwise rich-ens, counterclockwise leans. Fisrt thing I would do, get a new 02 sensor, as your has prob. not been serviced in a while (30k service interval on 02 sensors on your car) when the o2 craps out, ecm goes to a fixed rate duty cycle on your freq. valve, most always on the rich side to keep it from going to a lean situation, (not good) check the 02 relay under the pass seat, as most don't work, they run very warm and have a high fail rate. (turn the key off and on and your can feel it clicking) you must get the correct Bosch relay as the uni 5 pins from the part store will fail in a week or two. 20 bucks from our host, you can get a uni bosche 02 sensor at orillys for 19.00. Once you have an operable 02 system, as Paul posted above, go to the zone and get a dwell meter, will be all you need to get your mix in shape.

[Jim Williams]

There is a lot of "professional" level CIS advice on this forum, much of it covering the Lambda systems of the '80 - '83 US CIS cars.

psalt has some good posts, and there is some info on the link in my signature line below.

[JCFL]

Thank you all for your comments. i might try with the O2 sensor verification. As to taking the car to a local expert, that is precisely the problem. For me, local would probably be about 500 miles !

Thanks again.

JCFL

[don gilbert]

No need for high dollar shop diagnosis, everything you need is here, you are just going to have to invest in a few tools like cis gages, a dwell meter, and a Bentley service manual. CIS is not as complicated as most think, and actually kind of fun to diagnose and repair. (for me anyway) I have been modifying and playing with mine for just a few years, and understand it throughly. I enjoy troubleshooting my local pals cars, and haven't come across one yet that we couldn't straighten out, and ive had some tuff ones, mainly because they took it to a "expert" who messed it up even more. Most every k-jet car that pulls in our little garage complaining of rough idle, black smoke, poor acceleration have lambda control probs, which really make cis run like crap. A dwell meter will tell you right of the bat if it is working or not. Most repair books will tell you the proceedure for testing, but i like Ben Watson's "how to tune and modify cis" is one of my favs, as it has way more trouble shooting tips than the Bentley

[JCFL]

bump

[kodioneill]

The black on your bumper is from the audition of Ethanol to Gasoline. Put a little gas on a rag and it will come right off. The front spoiler looks like it's from a Carrera not a SC.

[JCFL]

Hello Kodioneill,

I am in Eastern Canada (province of NB). I am pretty certain that there is no ethanol in the fuel, in these parts.

You are correct on the valence, which is original to the 84-89 models. I was happy that it was installed by the previous owner, on this 1983 model.

Thanks for the input . . .

JCFL