Does anyone know what this is???

[gyxffyg]

I recently purchased this 73 Satellite and working through some issues and noticed mounted on the firewall is some type of vacuum valve. It is currently not hooked up to vacuum hoses and I am wondering what it is and what it does, or supposed to do. The car does crank and run although it could run better when cold. Can anyone tell me what it is? The connections are marked as "Dist" and "Carb". Anyone got a picture of how there's is hooked up?
Thanks

 

[Beekeeper]

not 100% sure but could be the idle up for the A/C

 

[Badvert65]

It is a vacuum switch. It senses air temperature (at the firewall air box in this case) and switches vacuum (from carb) on or off (to distributor) as a means of controlling emissions. You will typically see these either on the firewall or on the air cleaner housing. Back in the day, we typically bypassed these things.

 

[Brandy]

We typically ripped that crap off and tossed it in the trash bin....

 

[idrivemopar]

That is the OSAC valve, Orifice Spark Advance Control, basically helps to reduce the amount of Nitrogen oxides in the exhaust when temperatures are above 60 degrees by delaying advance of the spark under certain conditions.