Carter BBD vacuum port

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ben littleton

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Hello, i recently picked up a 65 dart automatic with a 273 and a Carter bbd. The car has been converted to electronic ignition. I have been trying to tune out a rough idle. First i adjusted valves, they were all on the loose side. Set timing to 8btdc static, advance plugged. The car is pulling 16" vacuum at idle, and it's steady even with the rough idle. The idle screws were 3 turns out, and they don't make much difference until they're about closed.
What i noticed is that someone plugged the vacuum port on the passenger side of the carb body and have the distributor plugged into the vac port on the rear, which also controls the choke pull off. Is that a ported or non ported hole? If dizzy needs to be plugged into the passenger side port by the bowl, I'll probably have to replace this carb, it's plugged with a screw that's cut off
 
Post some photos.


67 dart 273 bbd
My choke pull off is to the rear port.

Dist is on the side.
20180917_125343.jpg
 
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That's incorrect and likely what's wrong. The distributor needs ported vacuum. Also, the choke pulloff should have its vacuum source dedicated manifold vacuum. In other words, nothing else piggybacking. Most likely someone either broke the nipple off that's plugged, or it came out and perhaps was misplaced. They do come out sometimes. I may have one I can send. If you remove that plug and it's not broken off, let me know.
 
I don't recall but I think it is manifold vac. Put a guage on it to know for sure.

I bet with a little work you could get the screw out.
 
I successfully removed a idle mixture screw that was broken off on a CAP carb with the set screw that keeps it in place.
 
Another question, how much side play is acceptable in the butterfly shaft? I have a full millimeter, im wondering if a bunch of air is getting in through that.
 
RustyRatRod said:
That's incorrect and likely what's wrong. The distributor needs ported vacuum. Also, the choke pulloff should have its vacuum source dedicated manifold vacuum. In other words, nothing else piggybacking. Most likely someone either broke the nipple off that's plugged, or it came out and perhaps was misplaced. They do come out sometimes. I may have one I can send. If you remove that plug and it's not broken off, let me know.
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Will do, ill drill it out tonight
 
RustyRatRod said:
That's incorrect and likely what's wrong. The distributor needs ported vacuum. Also, the choke pulloff should have its vacuum source dedicated manifold vacuum. In other words, nothing else piggybacking. Most likely someone either broke the nipple off that's plugged, or it came out and perhaps was misplaced. They do come out sometimes. I may have one I can send. If you remove that plug and it's not broken off, let me know.
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I got it drilled out, turns out it was just full of rtv
 
Now you just need a tube. You could use copper in a pinch
 
ben littleton said:
Looks like 1/8 but ill measure it. Ill grab some copper tubing tomorrow. Hopefully that sorts out the idle. How much slop is acceptable in the throttle shaft?
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I just made a post on that a few days ago. I think most people make too big a deal over it. The "air in" will take the path of least resistance and that "AIN'T" through throttle shafts that are "a little" sloppy. Now of course, if it has a lot of wear, it'll certainly affect it.
 
RustyRatRod said:
I just made a post on that a few days ago. I think most people make too big a deal over it. The "air in" will take the path of least resistance and that "AIN'T" through throttle shafts that are "a little" sloppy. Now of course, if it has a lot of wear, it'll certainly affect it.
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Ok ive got a rebuild kit on the way for this carb, not sure if its ever been done. Ive done several eddys in the past. Hoping to get my idle vacuum above 16"
 
ben littleton said:
Ok ive got a rebuild kit on the way for this carb, not sure if its ever been done. Ive done several eddys in the past. Hoping to get my idle vacuum above 16"
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You may need to re-time it once everything is correct.
 
In a recent post @AJ/FormS or @67Dart273 (I think) outlined a procedure to setup and tune a carb.

Word of caution... The jets and rods are not available. Unless you have a proper removal tool I would not remove them.
 
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Dana67Dart said:
In a recent post @67Dart273 (I think) outlined a procedure to setup and tune a carb.

Word of caution... The jets and rods are not available. Unless you have a proper removal tool I would not remove them.
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Good to know, thank you. I have a lead on an eddy 4bbl intake, so worst case, i may just swap to a quad
 
ben littleton said:
. Set timing to 8btdc static, advance plugged.
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You have two problems.
The first is the 8* advance which puts the throttle blades too far down on the transfers and maxes out your mixture screws. and
The Second is re-hooking the Vcan to full-time manifold vacuum, which at 16" vacuum pulls it ALL in, and adding it's load to the initial. So now at the rather large amount of idle-timing, the engine runs too fast, and the only way to slow it down, slams the door on the transfers, so yeah
I'm surprised it runs at all.

so
disconnect the Vcan until you have a working Sparkport.
Open the mixture screws to 1.75 turns.
Idle up the engine with the Curb idle screw, until the engine smooths out.
Back off the timing, to slow it down, until she no longer bangs into gear.
Fine-tune with the mixture screws.
Repeat as may be necessary.
This is a starter tune.
 
Ok ive got everything hooked back up. Dizzy is on ported vacuum, and no vac signal at idle . I dialled advance to 0 btdc to start with. I am getting a strong 20" vac at idle from the port on the intake that feeds the hvac system. Problem is thslat i have a miss at idle and no load cruise, only on the left bank. The car runs good under load. The idle screws dont seem to make much difference to the miss. Where should i start?
 
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