What is this thing? And is it important to be plugged in?

[Mackeath]

I assume it is but as I was looking around for my temp sender wire, I noticed the thin hose was not plugged into the little longish cone shaped plug. So I plugged it in. What is it?

Thank you for your knowledge, I really appreciate it!

 

[Mackeath]

Here is a shot farther back to help get an idea of where it is.

 

[rusty_tlc]

What year is your truck?

 

[deltapine1]

Bi Metal Vacuum Switching Valve - BVSV

 

[Mackeath]

It is an 88 fj62. What is a Bi Metal Vacuum Switching Valve? It was unplugged for I don't know how long. What would that do?

And thank you for the info!

 

[rusty_tlc]

It is an 88 fj62. What is a Bi Metal Vacuum Switching Valve? It was unplugged for I don't know how long. What would that do?

And thank you for the info!

Part of the emissions controls.

Unless SOSTM chimes in you will need an emissions control schematic to figure this out.

 

[deltapine1]

BVSV - it is threaded into the thermostat housing and allows vacuum to pass through when it senses a certain temperature. I am not sure about the 62's but the 60's have two of them. Each opens at a different temp. You may only have one on a 62 as one if them on a 60 controls the choke breaker and fuel injected vehicles don't have a choke. It could be for cold start fuel enrichment.

I think you need a 62 guru or an emissions manual and be darn careful as the hose connections usually break off the BVSV's easily!