Distributor hose routing help

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Futzy1

Futzy1

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Well I think I'm about to show exactly what an auto novice I am, but I've looked and looked, and decided to "suck it up" and take my vacuum advance question to the group. Yes, that was a HORRIBLE pun.

I have a 73 dart custom with 225 slant and all those glorious early emmisions control devices. I went to check the timing, and found that my distributor vacuum line was severed. (Although the car feels like its running fine) when I did a quick search for the routing I found this diagram for 1975 that shows two hoses coming from the distributor. The red hose to the nipple on the air cleaner housing next to the hot air intake, and the black to the vacuum port on the holley 1920 carb,. However mine was only setup the "red route" to the air cleaner.As I said I am a novice at this, and I'm wondering if I'm supposed to have some sort of "t?" Is it routed properly? (Minus the severed hose of course.) Fill me in guys. Is that just a '75 and not a '73 thing? What am I missing here?
20180418_072526.jpg
 
i would route it to the carb, but then again, i live in a place where you dont have to pass smog test and what not
 
diymirage said:
i would route it to the carb, but then again, i live in a place where you dont have to pass smog test and what not
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Not an issue. CA doesn't smog any gasoline vehicles before the model 1975. Honestly its half the reason I buy pre 75 in the first place.
 
i would put a cap on that line nipple on the air filter and run the vacuum advance to the carburetor
 
Futzy1 said:
Well I think I'm about to show exactly what an auto novice I am, but I've looked and looked, and decided to "suck it up" and take my vacuum advance question to the group. Yes, that was a HORRIBLE pun.

I have a 73 dart custom with 225 slant and all those glorious early emmisions control devices. I went to check the timing, and found that my distributor vacuum line was severed. (Although the car feels like its running fine) when I did a quick search for the routing I found this diagram for 1975 that shows two hoses coming from the distributor. The red hose to the nipple on the air cleaner housing next to the hot air intake, and the black to the vacuum port on the holley 1920 carb,. However mine was only setup the "red route" to the air cleaner.As I said I am a novice at this, and I'm wondering if I'm supposed to have some sort of "t?" Is it routed properly? (Minus the severed hose of course.) Fill me in guys. Is that just a '75 and not a '73 thing? What am I missing here?
View attachment 1715166492
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See if you can find a '73 diagram - as mentioned last night over 'coffee', by '75 they were included on a sticker in the engine compartment. Not sure when they started that.

However, IMO OSAC is a PIA. I'd do what Diymarge said. Cap or eliminate the Tee, and cap the extra port on the vacuum advance.
Came on all models in '73. Probably get better throttle response without it.
1973 Imperial and Chrysler Clean Air System Reference Service Repair Book from the Master Technician's Service Conference (Session 302)
 
I've read from slantsix dan about bypassing the the osac, so that is done. For now I've done basically what you guys said and just ran the line direct to ported manifold. There was no T which is what was confusing me. The only line from the distributor was to the air cleaner and the ported vacuum was just open.
 
Well, fun and interesting development. I went out to check the timing last night to check the timing, and as I just gave myself an internet masterclass on vacuum advance yesterday, I figured I would give a little sick on the hose to the distributor hose just to see it in action. . . . Nothing. I still need to double check it was not a bad hose, but I'm pretty sure it's not the hose.

Anyways, guess who gets to learn how to install a new vacuum advance today.
 
Did you use a Mityvac or the mighty lungs?
 
Just my mighty lips. (Super healthy.) It was like sucking on a straw.
 
Oh, so you think there's a hole in the diagphram or the housing?
Is there a cap where the red line attached?
Could put your finger over it to verify the connection since you suspect the hose.

As far as a new Vac module. See what is suggested in the slant six subforum here and there's a couple bulletin boards dedicated to slant sixes. Maybe search for OSAC delete with Vacuum advance.
 
So, I pulled the hose from the carb end, and left it on the distributor. I do know that the hose is securely attached on the vacuum advance can. I have a section of hose here that I know is good so I'll pop that on and dbl check, but I'm fairly certain it's not the hose (words that always bite me in the ***).
 
I've not studies the OSAC valve. Even though I had several 6s with them - it was long before I knew much about what they did - I did know those cars were slugs compared to the earlier cars I drove. Anyway I'm assuming from the diagram above its a controled vacu leak that closes over 15 seconds, but I could be wrong.,
 
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Mattax said:
On this page, from '73 MTSC, it just shows the OSAC as an in-line valve. Maybe that's what your car has/had. It would explain no tee and also only one connection on the vac canister.
1973 Imperial and Chrysler Clean Air System Reference Service Repair Book from the Master Technician's Service Conference (Session 302)
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If you need a new canister, you can (a) see what the vacuum timing specs are in the shop manual. (b) open the distributor and see if the arm is stamped with a number. That only gives the total advance possible but its better than nothing. Then see what's available new and from old stock.
 
I kinda just want to say F* it and grab and upgrade the entire distributor. Alas with all the stuff I'm taking care of at the moment, the cost takes it off the "do it right now list."
 
If the canister is leaking, just put a golf tee in the hose from the carburetor port. The engine will run fine without it. Come back to it later. Mostly helps with mpg.

The Chrysler distributor is a good design. I wouldn't give up on it.
 
Futzy1 said:
Doesn't it also give you a little more throttle response? Not that it really matters its definitely going on the back burner for now.
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I think in some instances it may do that in the mid throttle range.
 
Futzy1 said:
Well I think I'm about to show exactly what an auto novice I am, but I've looked and looked, and decided to "suck it up" and take my vacuum advance question to the group. Yes, that was a HORRIBLE pun.

I have a 73 dart custom with 225 slant and all those glorious early emmisions control devices. I went to check the timing, and found that my distributor vacuum line was severed. (Although the car feels like its running fine) when I did a quick search for the routing I found this diagram for 1975 that shows two hoses coming from the distributor. The red hose to the nipple on the air cleaner housing next to the hot air intake, and the black to the vacuum port on the holley 1920 carb,. However mine was only setup the "red route" to the air cleaner.As I said I am a novice at this, and I'm wondering if I'm supposed to have some sort of "t?" Is it routed properly? (Minus the severed hose of course.) Fill me in guys. Is that just a '75 and not a '73 thing? What am I missing here?
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20180418_072526-jpg.jpg


These are not two hoses, rather one or the other
If you have the OSAC then you plumb it as shown, otherwise use the black routing. I recommend to bypass that OSAC, if your engine doesn't detonate routed that way
 
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