1973 Vacuum Diagram?

[morencycollege]

Does anyone know where I can get my hands on a vacuum diagram for my '73?

I have disconnected Vacuum lines that I cannot figure out where they route.

One line coming off the vacuum tree at the back of the engine has not been connected to anything and definitely has vacuum. When I plug it, it slows the idle.

In the front, I've got 2 lines disconnected, one at the vacuum advance and another coming off a tee. Thing is, none of these lines seem to have any vacuum

On the bottom of the air cleaner, there are 2 nipples, one is connected to a line going to the pot on the top of the air cleaner snorkel, but the other one is not connected to anything.

only relevant improvements that have been made that I can think would affect the system was an electronic choke and a brake booster that were installed a few years ago

I'd love to know the proper setup

 

[morencycollege]

https://photos.google.com/share/AF1...?key=Qm9FdGMzektIVzZ1SHlSU0FvWm11bGE4NTBXNE9n

https://photos.google.com/share/AF1...?key=Qm9FdGMzektIVzZ1SHlSU0FvWm11bGE4NTBXNE9n

 

[Action]

auto or 3 spd. ?

 

[morencycollege]

Automatic

 

[broncogt]

I know the retard side of the dist. can get full manifold vac.

There where lots of changes in the 70's. I used an econoline diagram that match the stuff under the hood of my 74.

 

[jckkys]

The 2 lines to the C4 tell us it's an auto. The rest of the black spaghetti is a little more challenging. The '73s are the worst with, EGR, Thermactor, a weird ambient temp. switch in the A pillar, multiple PVS valves, and vacuum advance retard. I would take on one system at a time when possible. They seem to be interdependent, so that's not easy. My Chilton manual only covers a few. Some of the old Motor manuals have a little more. In later years Ford made a electrical/vacuum trouble shooting guide. I have one for '87 Crown Vics. You may be able to find '73.

 

[DirtDonk]

If they were archived and are hidden where all the other old stuff goes to die, I remember in the early days that either Kragen/Schuck's/Checker or one of the other major chains (Grand Auto maybe?) had the most amazingly detailed listing of vacuum diagrams for literally hundreds, if not thousands of vehicles.
If someone remembers that and knows how to search the internet archives we might be able to come up with the '73 specific diagram.

Just like we now have for all the RJM technical info that disappeared with Ryan's site, it's available through the archive system.
I guess the other option would be if someone has a factory Ford manual on CD.

Paul

 

[AC932]

Here's a picture that's been floating around for a while.

Personally, I would probably disconnect most of the lines for your EGR and dizzy and start them over. I also wouldn't worry too much about having the OE system exactly, especially when it comes to the distributor advance/retard stuff.

Starting with your tranny. Looks like that's probably properly connected, with 1 line going to the manifold, and the other line tee'd into the EGR line. The EGR line is connected to the EGR ( ) and the other end of it is connected to the vacuum switch on the heater hose outlet thing on top of the intake manifold. The other nipple on that switch goes to the EGR port on your carb (located under your accelerator pump).

It looks like other than the connection from that switch to the EGR port, your EGR setup is probably fine. That said, there are also setups that integrate your EGR and distributor advance using all sorts of fancy valves that are hard to find.

As far as your distributor connections go, I would just connect your advance (front distributor nipple) directly to the spark advance port on the passenger side of the carb.

The dizzy port on the rear (which currently has a hose to nowhere) can be connected to full manifold vacuum. That retards timing at idle for emissions. You can also just leave it disconnected and it won't really effect anything.

Again, there are a ton of different systems for the advance/retard routings. The one in the picture uses a vacuum switch that should replace the plug in your thermostat housing. Most of these systems are primarily concerned with emissions, and if you're not required to pass that, it's likely not worth the effort in finding some of these parts.

 

[jckkys]

I had an original '68, '74, and '77. We know the emissions standards grew more stringent as years went by. Oddly the number of emission control devices on Ford small blocks decreased in later years. My '77 had no distributor retard, 2 port vacuum modulator, ambient temperature sensor, or Thermactor (air injection). It did have EGR and 2 PVSs to control the EGR and vacuum advance. The emissions laws accept later systems to replace earlier systems. In the case of '73 EBs the spaghetti could be simplified by using the '77 emissions equipment and be legal. If your '73 passes the sniffer, the inspection would be no problem. The inspectors are no geniuses they usually just look for EGR.

 

[EPB72]

I had an original '68, '74, and '77. We know the emissions standards grew more stringent as years went by. Oddly the number of emission control devices on Ford small blocks decreased in later years. My '77 had no distributor retard, 2 port vacuum modulator, ambient temperature sensor, or Thermactor (air injection). It did have EGR and 2 PVSs to control the EGR and vacuum advance. The emissions laws accept later systems to replace earlier systems. In the case of '73 EBs the spaghetti could be simplified by using the '77 emissions equipment and be legal. If your '73 passes the sniffer, the inspection would be no problem. The inspectors are no geniuses they usually just look for EGR.

The emissions laws accept later systems to replace earlier systems.


Maybe this would be OK in Arizona ? But not all states would allow this,, In Ca. the above statement is a no go..

I may have a vacuum diagram I can check tomorrow and compare to what's already posted