What is "Power Control System"? (1 Viewer)

[finderscuba]

There is a device near my fuel filter that has me scratching my head. I came across it in the FSM but I still don't know what it does. Check page FU-95 for info. The device turns out to be a "VSV". I'm still clueless. I don't even know what VSV stands for.

Can someone please explain the function of the PCS and VSV? I'm thinking it has something to do with boost. But it looks like it only comes into play in 1st or reverse on a manual tranny - mine's a 5 speed.

 

[lumpy70]

Vacuum Switching Valve.
its something your truck controls with presence or absence of vaccum. Examples are push-button 4wd, your boost light, or in some engines the fuel delivery etc. There are lots.

Not sure what on would do in only 1st or reverse,

Craig.

 

[70sguy]

The AC idle up VSV is on the fender right near the Fuel filter tower. Two hoses lead to a vacuum pot that pulls in and bumps the idle speed up.
Should not be a factor right now.

 

[sandcruiser]

but there is also a "PCS" described in the FSM. It appears to be vacuum actuated in the FSM, but if my memory serves, there are electrical leads on the IP as well, and at some point I decided they were connected to the PCS...

so can any diesel guru tell us what the PCS does? Mine is disconnected. If connecting it correctly would add power or economy or driveability to the vehicle, I'd like to connect it (since its just sitting there anyway).