Vacuum hose routing

[Hemikiller]

Here's the 3-16A calibration vacuum diagram. Original PDF attached, found it here:   https://www.mustangbarn.com/technical-information



1973 3-16A.pdf

 

[RC92234]

That's the same as the marked up diagram Kingb posted earlier, without the markup. I think it would be correct for a non-A/C car. If I omit the PVS off the water pump from this "circuit" and change the manifold source, it's a fit. But then... what's the point in the PVS? It's normally the high temp emergency control for the vacuum advance so I can see it making sense to omit.

 

[Don C]

I believe your problem may be in trying to match what was on the car when you acquired it. You don't know what the previous owner did to the car or what some smog check station said it needed to pass. Assuming the valve covers are the original ones, it appears that you need the 3-16A calibration and vacuum setup. I would do what you need to match that diagram and call it good.

 

[Hemikiller]

I believe your problem may be in trying to match what was on the car when you acquired it. You don't know what the previous owner did to the car or what some smog check station said it needed to pass. Assuming the valve covers are the original ones, it appears that you need the 3-16A calibration and vacuum setup. I would do what you need to match that diagram and call it good.

That's what I'm thinking. The 3 port could have been a fix for a broken 2 port and those were out of stock. If hooked up correctly, they will function the same. 

Looking back at the pics in this thread - you seem to have some pretty clear shots of most of your vacuum lines and it looks like a 16A calibration from what's visible. 

https://www.7173mustangs.com/thread-from-the-top-%E2%80%9873-q-code-convertible

 

[RC92234]

I believe your problem may be in trying to match what was on the car when you acquired it. You don't know what the previous owner did to the car or what some smog check station said it needed to pass. Assuming the valve covers are the original ones, it appears that you need the 3-16A calibration and vacuum setup. I would do what you need to match that diagram and call it good.

That's what I'm thinking. The 3 port could have been a fix for a broken 2 port and those were out of stock. If hooked up correctly, they will function the same. 

Looking back at the pics in this thread - you seem to have some pretty clear shots of most of your vacuum lines and it looks like a 16A calibration from what's visible. 

https://www.7173mustangs.com/thread-from-the-top-%E2%80%9873-q-code-convertible

Well that's a whole new level of conundrum: the current 3-port valve is incorrect because it replaced a faulty 2-port.  If I could find a 16-A diagram for "with air conditioning" I'd be more confident in it.  But in 16-A, the valve in question is a temperature control valve and I can't quite tell where it's mounted, although it seems if were the water pump as the PVS is in 14-A, it would be positioned in the diagram differently.

AND, with the 16-A routing, supposing I went with a 2-port PVS valve mounted in the water pump, what is the 2-port TCV in the heater hose? Perhaps the TCV is related only to the emissions system?  No, I don't really expect an answer to that, but it sure would be nice to find the one magic diagram that explains it all.

 

[Don C]

Not all calibrations have different ones for with and without A.C. Some use the same calibration for both. It appears that applies to all 351C engines. I believe that you're looking for something that does not exist.

 

[RC92234]

It seems all cars used the TCVs, but only a/c equipped cars also use the PVS.

So if I go with 16-A — which uses a TCV, not a PVS, and the TCV is mounted in the heater hoses, what to do with the PVS mounted in the water pump? It must serve a purpose. That’s why I can’t quite accept 16-A as gospel.

 

[Don C]

Only the 250s and 302s have separate configurations for A.C. and non-A.C. engines. NONE of the 351Cs have separate configurations.

 

[RC92234]

You seem to be correct; I sit corrected. Nonetheless, still no idea what to do about the PVS vacuum circuit.

And as I look through the diagrams, only the 351c with 2-bbl and automatic seems (3-14a) to use the PVS, yet both VIN and the carb in the car are def 4-bbl. And only 3-14a shows the manifold vacuum source in about the same place as my car, but, 3-14a also shows before the vacuum advance an additional solenoid which my car doesn’t have.

The discovery continues (while I wait for other parts to arrive so I can get this put back together).

 

[Don C]

When David dismantled and detailed one of his cars for the Mustang Owner's Museum he took a lot of pictures of the process. You might look through his thread on it and see if you can find any engine pictures that show what you need

https://www.7173mustangs.com/thread-have-started-the-long-job-of-cleaning-the-73-mach-1

He has this one and some other unmolested cars with 351Cs and if you ask him there's a good chance he'll take some pictures of what you need. He probably already has them, but his computer crashed and he lost a lot of pictures, unless he has been able to recover them.

 

[RC92234]

Wow, thanks! What a great resource that whole post is. It will take some time to go through -- I only got through the first five pages. Hopefully there are more than just the first Mach 1; right off the top I see "15-A" and a two-port TCV, not PVS, in the water pump.

 

[Don C]

I think the only one he has in that thread is just that one.

 

[kingb1973]

What a great job of taking pictures as you go. David did a lot of work. Never fails though, the more pictures I see, the more I look, the more I want.

Can never have too many.

Got lost going through the thread and will now get back to focusing on the pics about the original question.....vacuum lines.

 

[kingb1973]

So looking at the 250 and 302 calibration schematics for 73 that I have access to, which is not many, there are similarities in those that specifically state with or without AC.

Specifically 3-8C, 3-9, 3-11C, and 3-11E, in that the main difference appears to be that when showing with AC, a 3 port water temperature actuated switch is introduced into the vacuum advance circuit to change from one vacuum source to another. Could one stretch this to the conclusion that if AC was added to a 351C calibration you would add the same type of circuit? Being the Clevelands have dry intakes, the choices for a water temp switch is limited. Helps explain why the 2 port switch for the EGR is in the heater hose.

Don't believe Ford wanted to spend too much time on this in 72-73. They were working on the next Better Idea......the Mustang II.

Probable that there really aren't any "magic diagrams" that show it all. In my opinion, calibration drawings are just that, they show Emission Calibrations and information. A "full-up" vacuum drawing would have AC lines, ram air, manifold vacuum trees, brake booster, choke, air cleaner, the double vacuum loops on the firewall, and so on. Too much data for one page I think. I would assume that other stuff would be in another section of a service manual. Perhaps there is something elsewhere that shows what happens when you add AC to a 351?? Perhaps in a Technical Service Bulletin?

Looking at this post 

https://www.7173mustangs.com/thread-have-started-the-long-job-of-cleaning-the-73-mach-1?page=5

which also appears to be an unmolested 351C with AC, you can see a 3 port switch in the water pump. In other pictures on the same page, it has been removed from the pump and is hanging next to the outside of the right valve cover.

No answers, just more questions.

 

[Don C]

If you want to research the TSBs you'll find a link in this thread.

https://www.7173mustangs.com/thread-ford-technical-service-bulletins?highlight=technical+service

Good luck.

 

[kingb1973]

That is one heck of a lot "o" Data. Should keep me busy for some time to come. Great link if I can figure out all the online navigation.

Thanks

 

[Don C]

If you find anything, please let us know, I'll update my thread with vacuum schematics.

 

[RC92234]

I skimmed through all the TSBs for late ‘72 and most of ‘73 but didn’t find anything relevant to this situation on the first pass.

 

[Don C]

Did you look at the '72 routing? Some of them look similar to what yours had. Emission controls were new back then and changes happened at various times and not necessarily at model year changes, and there were likely carry-overs.

You can find them here:

https://www.7173mustangs.com/thread-vacuum-hose-diagrams?pid=246021#pid246021

 

[kingb1973]

Went to the bookshelf several times this weekend. Swear I looked at the same stuff over and over. tried again and found this early this morning before going to work. Cannot verify the accuracy of what is shown here (Bad pictures of bad PDFs in a fairly good book), but it looks informative. Hope this helps.

Pics are of diagrams for 1973 EGR Equipped 351C in several combinations, (2V/4V, MT/AT, W and W/O AC). Still has some things like the air cleaner that do not look correct, but they do show 2 and 3 port temp switches, 4 port loop on the firewall, mechanical DVAC for manual transmissions, etc.

Have PDFs attached below of these and the 302 and 250. Think if you combine this with the calibrations that Don C has, it just may get you where you are trying to go.

 



I don't understand why there are 2 options for the heater hose mounted 2 port switch when having the auto transmission. Attached are pictured that show one type for the auto trans (18B402), don't know what the optional PN 18599 looks like.  The other picture is for the manual trans (18A568). PN 18599 images I can find don't make sense to me. I got these pics from other members when I was trying to figure out how the vacuum lines ran on my 73. 

Here is the link to that post:

https://www.7173mustangs.com/thread-temperature-control-valve-in-our-heater-hose

Also pic of the vacuum tree in the rear of the intake.







1973 EGR Vacuum Routing.pdf