What are and what do they do?

[Benny771]

Is there a way to test these? Previous owner must have done work to these?
Is there anyway these may have something to do with low warm-up idle?
Car idle's low and rough untill totally warm. 10 min drive.

[Ronnie's.930]

There is quite a bit of info about those in this thread:

Solenoid to dizzy vacuum line

[Benny771]

Great info thanks.
I still dont know what they are called? Checking price here.
Also how long they are used, 1min,10min ?

[JFairman]

not sure what parts listings call them but they are vacuum solenoids or you could describe them as single pole double throw vacuum switches with one side being vented to atmosphere.

they are wired in parallel so they both switch vacuum at the same time about 1 or 2 minutes after a cold start.
left one switches the air pump diverter valves and the right one blocks vacuum retard from reaching the distributor vacuum retard pot after a cold start so the timing advances a little which makes idle speed raise a few hundred rpms.

if you need more you'll find them in CIS K-jetronic Mercedes in junkyards and probably other cars with CIS, air pumps, and catalytic converters.

[Benny771]

Fantastic,

Thanks for the info.

[OSI930]

Change over valve