LI Steve

Hi,
Does anyone know what this vacuum line is for?
I think I might just have fixed my failing cruise control after 2 yrs of searching...

Brett Matthews

Steve,
Is that a capped line I'm seeing? Did you cap it off, or was it that way? Have you been able to follow it to it's other end?

LI Steve

Brett,
It's not capped - it actually belongs plugged into a connector underneath that cylinder just to the right of it in the photo. The other end is routed along the passenger side of the engine bay, towards the front of the engine, but I can't tell where it leads. I will try to snap a better pic.
Thanks.

jpitman2

If thats connected to the small cylinder with fuel hoses connected, its the vacuum supply to the fuel pressure regulator. When you shut the throttle, vacuum goes high, you need less fuel, high vacuum increases the fuel returned to the tank by pulling the diaphragm open against the sping - typically reduce psi from 37 to 30. Sorry, that wont solve your Cruise problem. If the other end is not connected to the throttle body or plenum somehwere, fixing that may change you power, idle or consumption a bit.
jp 83 Euro S AT 49k

LI Steve

OK - the other end of that thin hose connects along the passenger side of the engine bay (1st pic). Then, it runs to the front of the engine, and connects as you see in the 2nd pic.

Thanks again!

Brett Matthews

Steve,
Jpitman is right, that "cylinder" is a vacuum operated fuel pressure regulator (?).
But what I'm seeing, if the second of the second set of pics is correct, is that you have two vacuum operated items connected.

And I see no source of vacuum.

Better look again, and if my assumption is correct, someone has been in your engine compartment, and incorrectly reassembled your vacuum lines.....

LI Steve

Brett - Can you tell what that 2nd vacuum operated item is from the photo? If you're correct, then neither of them would be operational.
Sounds like it is time for me to break out the shop manuals.

Brett Matthews

Sorry Steve,
Reading and looking back over my post, and your pics, I mistook the first pic of the second set, for the second....

Anyway, the first pic is of the fuel pressure regulator, the first of the second set, is the vacuum operated breather to your charcoal canister, I believe.....

And the second of second set, is a bit confusing.... Are you pointing your arrow at a breather line, or what you think is a vacuum line??? Not knowing the early 32 valve engines at all, I'm betting the line is a FUEL LINE, coming off of a fuel pressure damper! It also has a vacuum line to it! And if you'll notice in your first pic again, there is another damper, to the "northeast" of your regulator.....

Yeah, the WSM may be your best bet....

Sorry again, for the cornfusion....

Sheesh, looking again, that can't be right..... Maybe I oughta shut my trap.....

Big Dave

Maybe this will help:

LI Steve

Thanks Dave.
If I'm reading that properly, then my connection between the air-bleed valve (14) and the Thermo Switch (13) was disconnected. So - anyone know what the thermo switch does?