BMW 3.0CSi throttle butterfly position

[Barry.b]

Hi guys
I am looking for advice please.
I only just got my engine up and running and I don’t know if a previous owner has made adjustments to her or not, but I do know she is running way too fast on zero throttle.
My engine is ticking over at approximately 1900 to 2000 rpm so I believe it is getting excessive air from somewhere.
I have checked all intake manifold gaskets and the all seem good.
I have noticed that the butterfly on the throttle body does not actually close completely .
If I shine a light behind the butterfly I can clearly see light all around between it and the throttle body housing.
Is that normal or should it be closed fully ?

If it should be closed I think I might need to loosen the shaft clamp bolt as backing off the throttle stop screw does not seem to allow the butterfly to close. ( please advise)

Then can I also ask should I adjust the air adjustment screw to get her to tickover normally ?

I have already rebuilt the auxiliary air valve with a new wax bulb so I believe it should be working properly, although I might temporarily bypass that system just to rule it out.

Then one last question, I set all of the timing to TDC when putting her all back together, so I think that means that my ignition timing might need adjusting/ setting
Is there a “how to “ for that somewhere ?

 

[sfdon]

Barry - the butterfly is open too much.
Disconnect the linkage and adjust.
Remember the idle adjustment screw!
It’s on the firewall side of the throttle body down low.

You can call if you want.

 

[Barry.b]

Hi Don
Yes I was thinking that might be the problem alright.
I will make some adjustments to it and see how it goes
Thanks again

 

[Barry.b]

Hi Don
I don’t have any throttle linkages connected yet.
So my butterfly needed adjustment in the throttle body itself .
I loosened the clamp bolt and moved the butterfly to the fully closed position .
Now when I start her she is ticking over at approximately 450rpm and is nearly cutting out.
At least now that the butterfly is closed that is my base line and I think I need to adjust something else now.
Should I concentrate only on the idle screw now?

 

[sfdon]

Adjust the butterfly screw to show 1 1/2 threads first

 

[Barry.b]

Hi Don
I have read that with the butterfly closed I should be able to rotate the throttle switch slowly until I get zero resistance across pins 45 and 17
I cannot achieve that with my multimeter attached, it seems to stay “open circuit “ .
Am I missing a trick by any chance or is my throttle switch faulty ?
She has 1972 stamped on it so it must be an early one.

 

[sfdon]

Adjust the big idle screw on side of throttle body next