1965 Mustang 289 vacuum system question

[Mudfly]

I rebuilt the Holley carb on my wife’s Mustang last winter.  Too much going on and just got around to putting it back on tonight.  (I know shitty to wait months to reinstall something when we should be driving it).

I have everything hooked up as I remembered it and then I see a loose hose that I have no recollection of.  It’s the vacuum hose to the distributor for the advance.  I don’t remember taking that off.  The hose is not long enough to reach any potential vacuum port and I don’t believe that it went to the carburetor.  (If it did I don’t know where.)  it has an aftermarket Holley 4 barrel carb (4160?) that the previous owner installed.  I’m not super happy with it but it’s what I have currently.

Here are some pictures.  A quick google search says that it goes to the vacuum control valve, but I can’t find that or know where it’s supposed to be.  

thoughts on where this is supposed to attach to? I have the carb attached to a what I assume is a vacuum line in the valve cover.  

 

 

 

[acem]

Don't know exactly about a 65 mustang. But generally the vaccum advance goes to a special port on the carburetor.

If someone doesn't speak up first, I will dig out my Holley book and find where the port is on a 4160.

[axial_al]

That vacuum line needs to be attached to an intake manifold vacuum source so the distributor can advance the spark under low load.  The after market Holley carburetor probably has a fitting somewhere on the base for that purpose.  It may have a rubber plug on it you can remove and attach that hose.  That last picture would be a control that would screw into the water port on the intake manifold.  I’m not sure a 1965 mustang would have that.  My 1984 f250 does.  The attachment to the valve cover is a pcv valve and does go into the intake manifold at the carburetor base.  Good luck.

[dieselman]

think you have the port blocked off with a plugged vacuum hose by the choke linkage. this should send a venturi vacuum signal to the vacuum advance i believe that era of fords did not use manifold vacuum at the advance......dieselman.

[Mudfly]

11 minutes ago, dieselman said:

think you have the port blocked off with a plugged vacuum hose by the choke linkage. this should send a venturi vacuum signal to the vacuum advance i believe that era of fords did not use manifold vacuum at the advance......dieselman.

I don’t remember plugging that line but that was a thought that ran thru my mind.  It’s not long enough to reach there.  I am starting wondering if it was ever hooked up. Which may explain why it has always idled poorly.

[supermechanic]

That 90-degree fitting between the PCV and the manifold vac line looks a lot like a repurposed GM HEI ignition wire boot.

[dieselman]

with venturi vacuum it will only advance the timing when the throttle plates open, or when you accelerate. check your vacuum advance to see if the diaphragm is ruptured,check your base timing too

[MTB98]

2 minutes ago, supermechanic said:

That 90-degree fitting between the PCV and the manifold vac line looks a lot like a repurposed GM HEI ignition wire boot.

Doesn’t look like a PCV valve. It does look like a plug wire boot. 
Agree that the distributor advance vacuum should be hooked to the ported vacuum switch that that you have plugged with a short piece of hose and bolt. Throw a vacuum gauge on there to confirm you have vacuum on that port when you open the throttle plate.  Using a vacuum port on the intake may give too much advance. 

[Mudfly]

Look like it is supposed to be the port on the side that Dieselman suggested.  
 

I will have to get some more vacuum line and a splice tomorrow get that hooked up.  I do not remember cutting that line but must have happened..  or as I said it was never hooked up.

thanks.

[Mudfly]

9 minutes ago, supermechanic said:

That 90-degree fitting between the PCV and the manifold vac line looks a lot like a repurposed GM HEI ignition wire boot.

Not my patch work, but you are likely correct.  Lots of things not quite right with this car.

[iowaboy1965]

Needs to go to ported vacuum, not full manifold vacuum. You don't want the advance kicking full in at idle. Ported vacuum gets stronger as you increase engine speed, to a point anyway.

I'd run a line to port in the your picture marked tuned spark vacuum 

[jeeper61]

On a Holley the port for the distributor vacuum advance is on the metering plate 

 

Some go trough a thermal switch screwed into a coolant passage in the intake manifold