Distributor shaft play (280SLC M110 engine)

[rbtoj]

I don't know much about ignition system, but I think something is wrong with my distributor. I have a lot of rotational play in the rotor shaft, like 10 degrees or so (see the video linked). I've heard that shaft play is not an issue with electronic ignition, but it doesn't look right to me, and currently is very difficult to adjust the idle.

Video here: https://youtu.be/jEzGDwghfws

Is this amount of play normal?
Thanks!

[Frank Reiner]

r:

Completely normal and correct.
There is a centrifugal advance mechanism below the magnetic pickup plate. That mechanism advances the ignition point as the engine speed increases.

[97 SL320]

Due to a slow internet connection I can't see the vid. However from what you describe, the rotation is the mechanical advance.

In another thread, someone had a sticking vacuum advance leading to erratic idle speed.

Have a look on an air cooled VW site for distributor cleaning and lube, yours should be mostly the same.

[rbtoj]

Thank you for the reply Frank and 97 SL320.
I didn't know I had a centrifugal advance. I thought the advance was only vacuum driven.

[97 SL320]

Mechanical advance increases with RPM , vacuum advance is applied at part throttle for better cruising MPG. Sometimes the emission systems alter vacuum advance however.

[andyslc]

Can I hi-jack a liitle bit and ask for a part No for distributor that doesn't use electronic and has only vacuum/mechanical.
Same 280SLC.

[Frank Reiner]

Originally Posted by andyslc

Can I hi-jack a liitle bit and ask for a part No for distributor that doesn't use electronic and has only vacuum/mechanical.
Same 280SLC.

Andy,
That information was supplied here:
http://www.peachparts.com/shopforum/vintage-mercedes/386527-kjetronic.html
Post #48 of your thread!!

[andyslc]

Good evening Frank.
Everything I search on those numbers takes me to VW four cylinder.
I have contacted an old friend in Germany who reckons he can help.

Tanks again.

Andy.

[rbtoj]

andyslc: if it is any help, this is the list of all distributors used in the SLC according to the service manual:

0237302002
0237302003
0237302005
0237304003
0237302017
0237304012
0237306045
0237304018
0237304021
0237304001
0237304010

I believe they are all electronic though.

[andyslc]

Thanks.
My search and google buttons are almost worn out. 😆
I'll have a look at those numbers.
Thanks again.
Not Tanks like last post, big fingers, small screen..