Six Pack issues and rebuilding

[HP_Cuda]

Sounds like a blown PowerValve (what kind is it? 6.5? I think stock is a 4?) based on your pictures Tommy this sucker is dumping fuel out of your center carb like a Top Fuel dragster.

Btw, what is your idle vacuum? I think you said it was like 12 inches or in that neighborhood.
 - Found it - "Now for the tuning. Running about 15 inches vacuum at 900 rpm. Timing at about 14 degrees."

So your powervalve should be a 7 or 7.5 for this much vacuum. But the 6.5 that should come with a rebuild kit would not hurt. Which one do you have on there again? It's stamped on the front part of the power valve and I cannot read it cause the flash made so much reflection in your pic.

I know this is a cheby site but has a cool way to testing your power valve:
http://www.superchevy.com/how-to/74058-carburetor-valve-problems/

[tommyg29]

Not sure, its somewhere in this thread but I think I have 13-14 lbs vacuum.
The numbers are hard to read but I think I had and have a 6.5 PV. I noticed the new PV was not threaded in tight. I was able to unscrew it with my fingers.
So, if you suck on the back side of the PV it should start compressing the spring and opening the valve with more vacuum, or does compressing the spring shut the PV? I would think more vacuum would open it, and normal state is closed.
Regardless, I cant operate it with the 5 pounds vacuum my vacuum cleaner sucks (I measured it with my vacuum gauge)
I just put my old PV back in and tightened it in good this time and will try again after the game 
Things may be making sense now, and if this fixes it I am pissed at myself for not catching that before now.

[Chryco Psycho]

Vacuum closes the valve , the spring will compress & the cone pulls inward to cut off the flow , more vacuum keeps it closed less will allow it to open with higher load on the engine , if it was loose that was the problem as you have 15" of engine vacuum pulling fuel past the gasket on the power valve , I assume you have a gasket in there !!
 to test tham I just use my mouth but 5 " of vacuum should not overcome a 6.5" rated PV anyway

[Strawdawg]

It was leaking out on the bench when not on the engine so it is either torn,  or very loose, if it's the problem

[cuda346pk]

Tommy. I think you have found the problem now but I do have a 72 factory manual that covers the 6 pack and the 6 pack engine handbook plus an old holly carburetor and manifold book by Mike Ulrich and bill fisher. If u need I can copy pages for you or am even willing to mail you the books to use until you figure it out.  It has to be pv,  gasket or Crack in body to get fuel like that and still have good float level.

[tommyg29]

Thanks for the offer, but
I think I am back on track now and getting closer 
Got it to finally idle and it isnt dumping fuel anymore. I think it was a loose PV.
Have the outboards mounted but not connected, and it is idling, but, as it warms up after a minute or two it starts smoking out the exhaust more and more. Then I shut it down and let it sit 20 minutes and start it up again, and did this routine several times today. Each time it seemed to idle OK. I set it at about 950 rpm. Hard to read but I think initial timing is in the 12-15 degree range. Idle needles about 3/4 to one turn out, and vacuum now seems about 8 inches at idle.
Problems are twofold for now:
First, after the first 30-45 seconds of running the exhaust starts smoking, and seems to get worse and worse the longer I leave it running. I am hoping this is just raw gas that probably was sitting in the exhaust. Hopefully this issue will fix itself but....?
Second, it is still dieseling badly each time I shut it off, and a few times it seemed to just cough and shut itself off after a few minutes idling. After I started it the first time today it had one huge flaming backfire belch out the carb. Hope the PV is still OK.
Not that I care for now, but my dash tach (an upgraded digital unit I think from 10 years ago) reads about 50% faster than the timing light tach. MSD issues I guess.

[Strawdawg]

That had to make you feel better after all the struggle!

If you have the end carbs mounted but they are not filled with fuel, it will make the car run very lean at idle because they are sucking air but no fuel.  That may have made you have to open the throttle blades on the center carb more than normal to keep it running.  When you supply fuel to the other carbs, you may be able to close the center blades a bit and the after run/backfiring may go away.

I am guessing the exhaust has been saturated with excess fuel from the flooding and allowing it to run and get good and hot will probably eliminate the smoke after a bit.

[tommyg29]

I did connect the fuel to the outboards but not the linkage or the vacuum tubes so that is probably the problem. I will connect them up tomorrow and see how it runs.
Just got so many things going on I never have more than a few minutes to spend on it. A funeral today, and tomorrow we're going out in several boats to drop his ashes in the ocean, then have a party in Stiltsville, then help my daughter move, etc.
Next two weekends are weddings out of town. You get the picture.

[tommyg29]

Had a spare 30 minutes this evening, so another update. After letting er idle a number of times for a few minutes each over the past few days, just tonight the smoke MAYBE started to clear.
But, it seems to only idle about 4-5 minutes then it abruptly shuts off with a big wheeze/cough out the center carb.
BTW, the secondaries are now fully connected up, fuel, linkages and vacuum tubes.

Also, whats with the vacuum less than 5 inches?
Could this be from a leak or uncapped opening? I checked everywhere I could. Maybe because I removed the choke assembly? I am pretty sure my numbers used to be in the 13-15 range.

Click the pictures below for photobucket video:

[HP_Cuda]

Tommy

You have to have a huge vacuum leak otherwise you have a race cam and don't know it. Seriously you cannot because I would hear the lope if you did.

Find the source of the vacuum leak and plug her up. The exhaust sounds like one of your cylinders is drowning in fuel.

B

[tman]

Your vacuum gauge is hooked to ported vacuum.  Need to find manifold vacuum, which is below the throttle plates.

[tommyg29]

Will do.
Thanks.
With it hooked up properly, I am going to watch the vacuum gauge more carefully next time.

[tommyg29]

Yippee
Took it to the gas station tonight for the first time since last year.
Put 8 gallons of 93 Chevron in it.
I have been idling it for 5 minutes at a time, and it still cuts off after about 5 minutes for some reason.
Blowing a lot less smoke, but still a tiny bit.
Vacuum reads about 10 inches now at 1000 rpm, and goes up to about 20-22 at 3-4000 rpm. It seems fairly steady at a given rpm, so it isnt fluctuating or jumping around (which I think would indicate valve or ring issues)
Also, I still cant seem to get it to idle steadily, as it warms up it seems to want to start idling about 1500-2000 rpm, and then when I turn the adjustment screw down it will idle normal, but then next time I start it a few minutes later (while still warmed up) it will bog, so I have to turn the screw in again to get it to get the idle up to around 900-1000, and then after it runs awhile longer it sometimes start idling above 1500-2000 rpm again.
During my first drive around the block yesterday it was warmed and idling normally, but when I drove it up to about 3000 rpm it wanted to stay up there. I drove it home and pulled in the driveway with it "idling" about 3000. 
At least today it ran better, so I am making progress 
Still playing and trying to figure this thing out.

[cuda346pk]

Make sure all your throttle plates/shafts move freely thru full range. It's real easy to tweak the bottom of these 2 bbls and the shaft hangs open somewhere. I have learned to be very specific and carefully torque my carbs after replacing a couple. I still need to send you back the one you loaned me by the way. I am debating on heading to the keys layer this month if I do maybe I can  stop by and have a gander at it.

[mopar jack]

Make sure the linkage shuts the outboard carbs tightly. If they open even a little you'll have idle issues. Also make sure   the vacuum advance is disconnected and the vacuum port plugged. It sounds like you are close to getting it done.