Iwanna928

I had a vacum line unpluged and the car was set way rich to compensate for this condition. When I plug the hole the car runs very poorly. Greg said it was pig rich. The unpluged line or metall piece is on the passender side of the engine bay and looks to be coming out of a round piece like a diaphram or somthing.

I have pluged the hole and I am trying to lean her out. Have no clue what I am doing. Sometimes I wonder why I try but here I am.

When I put the 3mm in the slot to turn left or right I have some questions that I hope can be answered. The piece that I am turning seems to ne on a spring. Does the spring have to de depressed to actually accomplish what I am trying to do or do I just turn it. When depressed the cars idle seems to change, rhe noise that is. It is a deeper tone.

To lean it out do I turn clock wise or counter.

I read a tread on tuning and it stated to turn it and lean it out until it stalls, then do it again in the other direction and find a middle spot a degree or so to the richer side snd set it.

I am afraid to push down to hard as I don't want to break anything and it I turn it without pushing down it seems like little is happening.

Any tips?

Stephen

blown 87

His port off of the throttle body that maybe goes to the charcoal can was gone, but Stephan wanted to set it himself. lol
Yes, the CO adjustment is "kinda" on a spring, it is on the fulcrum between the air plate and the pin in the metering head.
So it can feel like it is sprung, you have to get the right tool into the allen socket in the hole, a little goes a long way.

We still do not know why it is rich, is it due to some one fooling with the CO setting? injectors not having a fan spray?

Have not checked control pressure or any thing on it, this is a stab in the dark for Stephan.

Iwanna928

Stab in the dark, that is funny. I have a better chance at winning the lottery.

The only good thing is that I can unplug and out her back to the way she was so it's worth a shot..I quess. Should probably stick it on a dyno to get a proper ratio.

So do I push down to turn and which way is which, lean to rich, righty tighty, or lefty loosey, OH WELL!

blown 87

You do not have to push down, but the allen has to fit into the socket, sometimes I kind of angle them and pull up, or push down to keep them running.

As far as left or right, damned if I remember, we use a four gas the set them.

gbgastowers

When you lightly press down the spring it bottoms out in the working area. It will go farther if you press on to the very bottom. Don't do this. This just pushes the air plate open. From Dr. Bob today "CIS does not depend on the "injector" nozzles for anything more than dispersing the fuel in a fog just above the intake valve. They aren't used for metering flow at all, so a rich condition won't be caused by the nozzles. Flow is determined by the metering unit, commonly referred to as the 'fuel distributor', and that flow is also determined by control pressure that's managed by the warm-up regulator. The basic system pressure is managed by a spring-loaded pressure control valve in the metering unit.

The ONLY way to determine proper function of the pressure control valve and the warm-up control presure regulator is with a set of CIS pressure gauges.

Only after proper control and system pressures are set, actual mixture settings require a CO meter of some sort in the exhaust stream. There are wide-band exhaust-gas oxygen sensors and meters available that make the measurements relatively simple. But that system requires a port in the hot exhaust piping right behind the engine, where the sensor can see hot exhaust before any cats or mufflers.


Conclusion: Buy/beg/borrow/rent a set of CIS gauges. IIRC, Roger has them available in his 928rus store. You may also find a local owner that has a set. They are common to virtually all CIS cars, including MB, Saab, Volvo, etc from the mid-70's to early '80's, meaning that a good local repair shop is likely to have a set. Once that's done, you can adjust the airflow sensor plate to get the final CO numbers dialed in perfectly.

In my limited experience, there is no substitute or shortcut method to setting up the system with gauges and the CO meter. Some folks can back in to a group of compromise settings that might allow the car to run, but the only way to get things right across all conditions is to start with a clean system, set up with correct pressures, then tuned for correct exhuast mixture. Anything else is like throwing darts at a small target in an blacked-out room.
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gbgastowers

CW richens and CCW leans

blown 87

We work on so many different models, I just could not remember, and wont again tomorrow.
Pretty simple when looking at a four gas though.

blown 87

Stephan, you are welcome to come down and use our gauges and four gas, on a day we are not covered up with work.

jpitman2

Do a search here - IIRC, its richen until it stumbles, then back a bit. Revs should rise as you lean it, up to a point. This setting will change with pressure changes, so its best to get the hot control correct - not that its easy to change if its wrong - usually a clean out of the WUR, or maybe a rebuild. If its near spec, adjusting to AF ratio should be enough. Check that the cold start injector is not fired all the time .
jp 83 Euro S AT 53k

928mac

Sounds like Greg knows what he is talking about and could do these in his sleep.

Sometimes we mechanics require a feel for things and sometimes it even amazes us at how close a trained feel can get.
Still checked with the tool of coarse

I hope you get it set.
I think cw leans and ccw richens

Iwanna928

Well I just got the kids down to sleep! Now I will check this out. Thanks.

Greg I might have to take a drive. I will call you tomorrow either way!

blown 87

We used to do a lot of them, but it has been a while.
And yes, like anything else, when you and I do it so much we can get really close with out any kind of extra stuff.

Iwanna928

Well I pluged the port. When this was done previously The car felt like it was running on 4 cylinders. I turned counter clockwise to lean her out and just listened to the idle till see sounded better. I took her out for a spin and she drives as smooth as silk. Yeah. I will get her to a dyno soon to find out were she sits. I have also have wanted to dyno her again as the last time the dyno temps were 108 degrees. Might still be a little rich but I sure didn't want to go to lean.

Thanks for you help guy's! Your all awesome!