What is this part?

[dewiant]

Hi guys,

Can you help me identifying what's this part? It looks like something to be connected somewhere to but it's not... And I don't know how it's called to Google it

 

[Sheriff41]

That's a ported vacuum switch, also called a thermostatic control valve. It directs vacuum to different sides of the vacuum advanced unit on the distributor based on the temperature of the engine. Your vacuum advance unit on the distributor has been replaced with a single function version (and doesn't appear to have a vacuum line connected) so the ported vacuum switch is not needed. You may want to connect a vacuum hose from a ported vacuum source to the vacuum advance unit on your distributor.

 

[Hemikiller]

That's an electronic PVS, and was used for vehicles with specific emissions system requirements. The electronic portion is a normally closed switch, and would break to open when the PVS reached it's activation temperature. This would often be used to disable an EGR system or a spark advance delay system when an engine was nearing a pre-set temperature.

The vacuum section of the valve would usually be hooked to manifold and ported vacuum. In normal conditions, the distributor advance would see ported vacuum. If the engine were to reach the pre-set temperature, the PVS would activate and provide full manifold vacuum to the distributor, advancing the timing and raising the idle speed in an attempt to cool the engine.

 

[SteveO_71]

It looks like you have the part on the right.
If you wanted to replace it, since they seem to be not found, you could use the one on the left, which NPD sells. I believe they typically have 3 vacuum connections.

 

[dewiant]

That's a ported vacuum switch, also called a thermostatic control valve. It directs vacuum to different sides of the vacuum advanced unit on the distributor based on the temperature of the engine. Your vacuum advance unit on the distributor has been replaced with a single function version (and doesn't appear to have a vacuum line connected) so the ported vacuum switch is not needed. You may want to connect a vacuum hose from a ported vacuum source to the vacuum advance unit on your distributor.

Yeah, I just disconnected vacuum for timing set. Connected it back afterwards.

Thanks all for the replies!

 

[mrgmhale]

Here is a YouTube video I posted that helps explain what these are, how they work, and how to test them...