1973 Swinger Vacuum Lines

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jpstewart19

jpstewart19

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Newbie so please be gentle....Just bought a '73 Swinger (Sunday) and it is running rough cold. Decided to check out the vacuum lines and finding a few odd things. My questions (for now) is:

The connector below in the manual shows only a single connection "Temperature Control Valve", but i have 2...part number shows as an ECG Control Valve...where does the 2nd line go or should I cap it?
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Disconnect it and run vac straight to the distributor. There is a reason it was one year only.
 
Just to be clear are you saying to connect the hose going to it from the Vac Amplifier and connect to the Distributor vacuum advance? If yes, then where should I go with the hose that goes to it now from the OSAC?

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Ok so bypassing OSAC makes sense and pretty straightforward. What about this firewall "temp control valve" with 2 connections that goes to the vacuum amplifier and also nowhere?

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The problem with Your situation is the proposed vacuum "re-routing" is going to give You increased vac adv with rpm, regardless of engine load, read detonation. The amplifier system uses venturi vac to control manifold vacuum, not ported , the diagram calls out venturi vac for that source. It is weaker, but increases with rpm/air velocity, which is why it is used to operate vac secondaries/outboards on Holley carbs. You will have less vac total adv., but it will be present when it shouldn't be, like WOT. I frankly don't know if the '73 carb has a "port vac" source tube, it may & be capped. Easy to check, should have -0- vac @idle, will jump up as soon as the throttle is opened.
 
Did 340 cars use that ? I recall my 73 340 4sp having a plate over that hole .
 
I thought it was a temperature delay for the EGR valve but I am talking out of my butt. I'm just following for knowledge .:eek:
 
mbaird said:
Did 340 cars use that ? I recall my 73 340 4sp having a plate over that hole .
Click to expand...
My 73 340 car also had a plate there. I figured it was because it was an export car. I have another 73 which was a 318 car and it was not blocked off.
 
I am ok with blocking or not, just not sure the full bypass procedure. I have 2 items on the firewall, per the pic...an OSAC and a Temp Valve with 2 connections (which btw when I blow through, air just comes out the other side). There is zero documentation on how this thing is supposed to connect. I get how to take the OSAC out of the loop, but not sure about this other device.
 
Ok I know its a long shot anyone is willing to watch, but slowly getting desperate...here is a video of my vacuum lines as they sit today. Open to suggestions
 
jpstewart19 said:
Ok I know its a long shot anyone is willing to watch, but slowly getting desperate...here is a video of my vacuum lines as they sit today. Open to suggestions
Click to expand...

Is there anything in particular You need explained in My above post? Or all of it? Almost every Mopar w/o the vac amp uses PORTED vacuum for the vac advance, Yours does not. You can leave everything else the way it is, just pull the dizzy hose & plug(well, cut & plug) at the amplifier, but You need a source of PORTED vacuum to attach the hose to. NOT Manifold vac, NOT Venturi, You need a vacuum gauge and check as I instructed. If the carb does not have a tube that is ported vac, You may have to get one that does.
Edit: yes leave the OSAC valve out of the loop.
Hope that helps. K6
 
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Being a "Newbie" I guess I should get to know HOW new, so here are some basics;
1) don't overlook basic tune-up items, they are step #1
2) the vac adv bypass may make the car run much peppier, but isn't likely to be the culprit in a "runs rough cold"
3) the temp valve is possibly a temp controlled vac leak & has no 2nd hose.
 
Thanks for your patience and detail. I understood about 50% to be honest and researched the rest. I now understand the diff. between ported and venturi vacuum.
2) This evening I will recheck per # 1 and determine if I this diz has ported vacuum. Sounds like an easy enough check with my vac gauge.
3) On your #3 above, just to clarify your statement, you believe this is possibly supposed to be just wide open at certain temps and left open? Very weird.

What drives me nuts about all of this is the lack of documentation and consistency of manufacturing. Coming back to Mopar after years in the VW world, while those Aircooleds have issues, every part is fairly consistent across model variations, numbered, and very well documented.
 
Item #3, yes. Just like a lot of vac control solenoids, there is a missing/dissintegrated foam filter for the open nipple. The valve should be open ~68degF and down, closed above. They were used 'til the middle of March '73, then replaced with coolant temp actuated vac switches in the rad. The image I have shows the hose on the bottom nipple, filter on top, look for any kind of marking to that effect. It is used to control the EGR, & may indicate such, or just "vac".
 
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Killer6 said:
Item #3, yes. Just like a lot of vac control solenoids, there is a missing/dissintegrated foam filter for the open nipple. The valve should be open ~68degF and down, closed above. They were used 'til the middle of March '73, then replaced with coolant temp actuated vac switches in the rad. The image I have shows the hose on the bottom nipple, filter on top, look for any kind of marking to that effect. It is used to control the EGR, & may indicate such, or just "vac".
Click to expand...

This makes total sense and explains the square foam thing I found online on this NOS ad when I was researching the part#

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Your sensor/switch appears inverted from the published images, but hose "center port" is correct.
 
Killer6 said:
View attachment 1715864124 Your sensor/switch appears inverted from the published images, but hose "center port" is correct.
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Thank you. I actually last night rerouted my hoses back to factory as a starting point, since it seems I lent out my vacuum gauge and never got it back. Seems to run a bit more evenly without any open gaps. I still want to do the bypass of the OSAC, but need to get another gauge. Hoping I dont need to replace my Carb.
 
Ok I have now found a carb leak and thinking of replacing. Based on the above is there a recommended carb that would provide Ported Vacuum. Current setup is an R6549.

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Sorry thats probably my fault. Mentally I had gone back to the suggestion of bypassing the firewall vc control and connect the carb to the vac advance. But was told i needed "ported vacuum" above, and since I am thinking of replacing the carb anyway due to leaks, I thought it would be the right place to request a suggestion on a logical swap model.
 
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