123 Distributor setup issue high rpm

Eko75

Eko75

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Hello,

When we setup the 123 electronic distributor on the CSI, the car revs at 3.000rpm... if we reduce advance at min, it doesn't go below 1500rpm but it doesn't work well.

Does anyone have the same distributor fitted? And any guess about why it behaves like this?

Thanks a lot
 
Which model 123 is it? Of all the issues with 123, this is one I’ve not heard of.
 
Are you letting the engine warm up so that you can ensure the cold start system is not causing your problem?

If so, I would first recheck that you had the engine at TDC when you installed the 123. Second I would check the ground - sometimes more modern electronics are sensitive to common ground problems so a separate ground with no other connections going to it can help.

I would then try making sure you don't have vacuum advance involved. Either plug the vacuum connection, or program the distributor so that you set vacuum advance to zero and then see if your problem persists.
 
I have been running the 123 6-R-V-IE since 2016 & sent it in for a rebuild twice. The 2nd time was for the helically milled spindle.

D-Jet CSi At cold start will be ~1500 rpm for several minutes depending on ambient temperature & atmospheric pressure. Idle should settle to ~ 900 rpm at operating temperature.
 
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We make progress, we switched advance curve from 7 to 6, it's an improvement.
Then with the vacuum connection plugged it's also a little bit better.

But the idle is still too high with the idle screw fully screwed. (really not sure about the vocabulary here).

I'll work on it this weekend...
 
Idle is controlled by 2 separate screws. Most likely the one on top of the throttle body is adjusted far from correct specifications. The large screw under the throttle body fine tunes the operating temperature idle, small adjustments clockwise or counterclockwise 1° to 5° yield vastly different results.

IMG_3716.JPG


Recommend following this Bosch D-Jet/L-Jet PDF File at the bottom of this page.

Published Sources

e9coupe.com e9coupe.com

This may be of help too.

DIY - 123 Distributor Idle Timing

So I've read some articles about advancing idle timing to the point where the vacuum and/or idle speed is highest then "backing it off" a degree or so to prevent pinging. This is the old school hot rod technique which while sipping my Manhattan last night I thought might have some merit. I...
e9coupe.com e9coupe.com
 
You didn't ask about this, but 123 distributors have horrible clips holding (some of the time) the dist cap. They are flimsy and get loose easily. allowing the cap to pop off. Corporate knows this and won't fix the issue. I wrap a zip tie around the cap holding the tops of the clips.
 
dwbower said:
You didn't ask about this, but 123 distributors have horrible clips holding (some of the time) the dist cap. They are flimsy and get loose easily. allowing the cap to pop off. Corporate knows this and won't fix the issue. I wrap a zip tie around the cap holding the tops of the clips.
Click to expand...
Yes, I bend my clips to increase the clamping pressure. Been this way for years, uncool that they have not improved these.
 
After knowing about the loose distributor caps on the 4 cyl. 123's, I checked my 6 cyl. 123. It is secure after 15K miles these past 4 years.
 
So we decided to get back the original ignition in place, then we went for changing the idle valve which wasn't working properly, found one on ebay, and now same issue.

You start and idle is fine, and the warmer the engine, the higher the RPM, if you change advance at ignition it gets down but it's not working properly, and if you put the right ignition setup, the idel is above 2.000rpm.

If I unplug this probe, it gets lower, but not enough.

20240524_120331.jpg

I'm lost here, I'm starting to think the issue comes from the igintion unit...
 
Yes, if you set it up correclty, idle is way to high when in temperature, if you move it you reduce idle speed but the engine is not working properly anymore.
 
Eko75 said:
So we decided to get back the original ignition in place, then we went for changing the idle valve which wasn't working properly, found one on ebay, and now same issue.

You start and idle is fine, and the warmer the engine, the higher the RPM, if you change advance at ignition it gets down but it's not working properly, and if you put the right ignition setup, the idel is above 2.000rpm.

If I unplug this probe, it gets lower, but not enough.

View attachment 183054
I'm lost here, I'm starting to think the issue comes from the igintion unit...
Click to expand...
Eko - if I am reading your post correctly, you are having this same problem with the stock distributor in place. If I have this right, I suggest you start another thread with a cross reference to this one. You will get more participation that way. Only a limited number of people will reply to a thread on the 123 distributor.
 
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