Vacuum Control line question

[yuth]

Hi
I need some help here please.
79’sc . Under the vacuum control. There is a line separate by a T connection. One end connected to the throttle body. Any idea where another end connect to? My is disconnected by accident while I’m working on removing the heat blower. Thanks.

[T77911S]

it goes to the thermo time valve (TTV) if you still have one. it is a small black device with an electrical connector going to it. the other side goes to the WUR (warm up reg) should be on the side.

[proporsche]

as previous post...i have a feeling that the T connector should not be on the bottom but on the top..as shown on the other post..look


here is another look at it notice no 11. and 14 is your T ..on top lines.........

[yuth]

Originally Posted by T77911S

it goes to the thermo time valve (TTV) if you still have one. it is a small black device with an electrical connector going to it. the other side goes to the WUR (warm up reg) should be on the side.

This is my TTV.
This one on the right goes to the T connector at the top of decel valve. Any idea?

[yuth]

Originally Posted by proporsche

as previous post...i have a feeling that the T connector should not be on the bottom but on the top..as shown on the other post..look


here is another look at it notice no 11. and 14 is your T ..on top lines.........

I have T on the top and also the bottom. I look at most of the diagrams . It goes one way to the throttle. That’s why I’m so confused .m

[yuth]

The bigger pic. The line with the blue mark is the one I refer to.

[SkiVT]

Take a close look at the path of your lines. The line from the center of the TTV should go to the decel valve. The line from the outer edge of the TTV should go to your WUR. Your lines appear to be opposite of that setup (see the diagram posted in response to your other post). It matters at cold start up as the TTV holds off vacuum.

Is the other line in question connected or want to be connected to your distributor? I am not saying it should be but I also don't see another line in the cobweb of lines in your picture that would come from the distributor to a vacuum source at the throttle body.

[proporsche]

as i said and pointed out ..i do not remember T fitting on the bottom look here.....
Ivan

[SkiVT]

+1

This is a great picture

[T77911S]

i was thinking it was off the top too but I have not looked at one in years


you should have 2 large hoses, one goes to a port above the throttle plate and the other goes to one below it. this is how it bypasses air around the plate.
you should have a smaller hose that goes to a T, one end goes to the TB below the throttle plate and the other end goes to the TTV then WUR.
there is a screw adjustment on the end of the DV. that adjusts how much vac is required to open the DV. I would suggest not adjusting it.
you CAN test the DV with a hand vac pump. it IS good to know about how much vacuum it takes to open it, then check engine vac at idle and make sure it is lower than the amount needed to open the DV.
you can also remove the DV and plug the 2 large ports on the TB and then connect the TTV line directly to the TB.
you might enjoy driving it that way.

[T77911S]

that is how I remember it.

you should not be able to blow thru it when it is closed

[yuth]

Originally Posted by SkiVT

Take a close look at the path of your lines. The line from the center of the TTV should go to the decel valve. The line from the outer edge of the TTV should go to your WUR. Your lines appear to be opposite of that setup (see the diagram posted in response to your other post). It matters at cold start up as the TTV holds off vacuum.

Is the other line in question connected or want to be connected to your distributor? I am not saying it should be but I also don't see another line in the cobweb of lines in your picture that would come from the distributor to a vacuum source at the throttle body.

So the red line should go to WUR and the blue to decel valve ?

[yuth]

Originally Posted by proporsche

as i said and pointed out ..i do not remember T fitting on the bottom look here.....
Ivan

Ivan
That’s why I was so confused.

[SkiVT]

Yes but it may not matter until you get the T at the decel valve straightened out.

[yuth]

Originally Posted by T77911S

that is how I remember it.

you should not be able to blow thru it when it is closed

T77911S
So if I want to remove Decel valve. I’ll need to cap Red and Blue. And Yellow connect to TTV ?

[SkiVT]

Assuming the picture labels are correct, which I believe they are, the answer should be yes.

Do you have a line from the distributor or not? The original line in question seems like an unanswered question.

[yuth]

Originally Posted by SkiVT

Assuming the picture labels are correct, which I believe they are, the answer should be yes.

Do you have a line from the distributor or not? The original line in question seems like an unanswered question.

[yuth]

Skivt
Yes I do have the line from the distributor to the TB (blue line). I’ll switch the lines on the TTV as well.

[SkiVT]

Maybe the line went to cruise control, based on this pic.

[T77911S]

for the hose to the dist.
there should NOT be vacuum at idle.
the vacuum should be there just after you come off idle.

you want the vacuum advance to start advancing as soon as you come off idle.
you can look at the ports on the TB and see were they are in relation to the throttle plate and then you can figure out which one goes where.
you can verify it with a timing light.
check it with and without the vac hose connected and you will see it working. you will also get advance from the mechanical advance but not as much early RPM's.

BTW, doing this stuff is a great way to learn and understand your car.

those are really nice pics BTW.