Fuel Distributor Issues

[Elvis]

Yes, That is correct when fuel pressure is on the system. The Co adjustment is attached via a piece of spring steel. The adjustment only effects idle. You can not manipulate the fuel curve of K jet by this screw. ...

Sorry Josh, I can't believe that.

I can't find a real picture of that screw and the parts around it,
but I found this as a nice overview:

bild05.jpg

Does somebody have pictures he could post here to prove and clear this situation ?

[Ron]

The only spring I can find around there in the 'Bosch K-Jetronic, Technical Instruction' manual is (#7 below), "A leaf spring ensures the correct zero position in the switched-off phase", but it is on an Updraft unit (Not DeLorean!)
UpDraftSectional.jpg

I knew I shouldn't have sold that spare unit I had

[Delorean Industries]

Cranking the adjust screw richer will not cause a richer mixture across the entire rpm band. Just at idle. The engine only needs so much air throughout the rpm band only moving the metering plate so far. After you are off idle the adjustment screw has no control. Everything is then based on the position of the air metering plate.

I know in theory it sounds like this screw would change everything but it doesn't. If that was the case and adjusting the fuel mixture across an entire rpm band was so simple I'm pretty sure everyone would be doing this in the last forty years compared to the other ways to manipulate the curve.

attached is the spring steel piece inside the metering housing.

[Delorean Industries]

If you really want me to I can attach a wide band to a car here. Cranking it rich and then move it through the rpm band and post a video of it.

[Elvis]

of course you have to disable the Lambda-System to do it.

I am pretty sure we measured it at idle and at higher rpms last time
I had it smog checked.

Any chance you can take a/some more detailed picture(s) ?

Thanks.

[Ron]

If you really want me to I can attach a wide band to a car here. Cranking it rich and then move it through the rpm band and post a video of it.

With all of the other fuel controls overlaying it, I don't see how that would help...

Speaking of the downdraft type, the manual says. "A counterweight compensates for the weight of the sensor plate and lever system (this is carried out by an extension spring on the downdraft airflow sensor)...."
If you would be kind enough to label the two springs in your pic, I would greatly appreciate it.

[Bitsyncmaster]

I would think the adjustment screw would affect the whole RPM range since it moves the air plate position. But of course you need to disconnect the Lambda from compensating for that adjustment. I seem to remember checking the FV duty cycle above idle speed and the adjust did change that.

[Delorean Industries]

You can not set the idle mixture to compensate for a need for more fuel at a higher RPM and vice versa. The Lambda system will compensate at different engine loads though.This has nothing to do with the mechanical base setting. Mechanically though it is not possible. with just the screw. Proving this is also difficult because if you jack it hard rich the car will not even make it into higher rpms off idle and will foul the plugs etc.

[Delorean Industries]

I'm trying to think of a good way to put this:

Once the air flow plate starts to move due to air flow any setting of that screw does matter and no longer effects the air fuel mixture.

[Ron]

I've been following you on that since your first replies...partially why I mentioned the overlying controls. What I don't get is the simple mechanics which you say would allow moving the screw and it not affecting the plunger height throughout the arms travel. I can see it would not be the same amount because the pivot is not centered WRT the contact points, but I can't see how it not be higher throughout (the original question).
If you would label the two springs, I can clear it all up in my thick head...