Six Pack issues and rebuilding

[HP_Cuda]

 

Try to disable the choke on the carbs for now until you figure out the whole problem.

B

[tommyg29]

The choke system has been totally disconnected, and the secondaries have been fully connected. I had the secondaries totally disconnected and the vacuum lines plugged last week and I just couldnt get the car to idle at all until I hooked up the secondaries.
I was getting very frustrated so I decided to hook them up and the car instantly seemed to idle much better (plus the power valve leaking which caused me a LOT of grief).
Anyways, the vacuum is at 9-10 inches now. Is that ok?
I should find a few hours over the weekend to fiddle with it. It seems the more it runs and the more I fiddle the better it gets. We'll see.

[tommyg29]

Ok, a question I cant seem to find the answer to.

- what is the at idle, or off position of the fuel pump lever under the main float bowl? That has a screw to set it, and I have tried to take all pressure off the lever at idle but not sure if its totally off. That does effect idle.

Just cant seem to get it to idle steadily. Either wants to run at 1600 rpm, or if I turn the idle set screw back even 1/16 turn it then wants to shut off. Pretty sure my outboards are as closed as theyre gonna get at idle. I have all 4 outboard idle screws set at 1/2 turn out (first picture is closed, second is 1/2 turn). The springs attached to the screws help a lot, especially the rear.

[tommyg29]

So glad I have it running now. Took it out a few times today, but it still isnt running right.
Idle is inconsistent. Sometimes it will idle at 1600, then Ill rev it and it will drop to 600, then after blipping the throttle it might go back up and settle at 1000. Seems to have a mind of its own.
I have been fiddling with all six idle screws but mostly the main throttle screw. All six idle screws are about 1/2 to 5/8th turns out.
Once today it just coughed and quit right out of nowhere, and still getting some dieseling after shutoff, but not every time.
Getting closer though
Btw, at about what vacuum should the secondaries open?
Revving the throttle in the driveway up to 4500rpm or so Ive never seen them open.

[brads70]

On post #272 what is that you have the vice grips on ? Vacuum line? ( I've never worked on a 6-Pac)  I see them also below the front bowl ( last picture) Could this be a source of a vacuum leak?  As far as the idle I had some of the linkage hang up on the intake slightly causing an inconsistent idle? A few minutes with a die grinder fixed it for me. Also open the throttle blades wide open to make sure they are not hanging up on a gasket/casting too.
Glad your making progress!    This would be prime cruising season in your neck of the woods I'd imagine?

[tommyg29]

Hi Brad,
Those are the custom "springs" attached to the idle screws for the secondaries. Helpful for adjusting the rear unit because without the upgraded base plate (which brings the adjusting screws out to the corners) you cant adjust them. The prior owner of these units attached these springs so I left them on, after of course rebuilding the rest of the unit and pulling the needles to check them and replacing the little cork seals.
I will double check your suggestions.
Thanks

[brads70]

Hi Brad,
Those are the custom "springs" attached to the idle screws for the secondaries. Helpful for adjusting the rear unit because without the upgraded base plate (which brings the adjusting screws out to the corners) you cant adjust them. The prior owner of these units attached these springs so I left them on, after of course rebuilding the rest of the unit and pulling the needles to check them and replacing the little cork seals.
I will double check your suggestions.
Thanks

Interesting. Again I have zero experience with these stock 6 pack set up so I'm enjoying learning from your posts .
I have though worked on dozens of Holley 2bbl's used in circle track racing assuming they were pretty similar other than choke stuff.  Not so it seems. Where those idle tubes/screws are from what I know would be a vacuum port. That's why I was thinking they were a source of a vacuum leak. I'll have to find a picture of one with the base plate off to see how they work .

[tommyg29]

The idle screws are basically set "front mid-bore" of each outboard, as you can see in the last picture, so the rear carb is impossible to get to without a special tool, or the way most people do it, by removing the carb. Of course thats a PITA, so I think promax and maybe someone else makes base plates that put the screws in the front corners so theyre more accessible.
I have no experience with Holley 2 bbls, but Ive worked on a lot of stihl and echo carbs? Of course ryobis are throw aways, but, you get the picture. 

[Chryco Psycho]

The 600 or 1600 idle is one of 2 things , 1600 rpm is running off the boosters , 600 is on the idle circuit so you need more air flow without uncovering the idle transfer slots so you have to drill holes in the throttle plates so it ill idle between the 2.
 It could also be in the mechanical advance , if the springs are too light it can change the timing at idle causing the speed to flare up

[brads70]

The idle screws are basically set "front mid-bore" of each outboard, as you can see in the last picture, so the rear carb is impossible to get to without a special tool, or the way most people do it, by removing the carb. Of course thats a PITA, so I think promax and maybe someone else makes base plates that put the screws in the front corners so theyre more accessible.
I have no experience with Holley 2 bbls, but Ive worked on a lot of stihl and echo carbs? Of course ryobis are throw aways, but, you get the picture. 

That's the" beauty" of this site everyone knows something and has something to contribute. Collectively we are pretty darn knowledgeable! 

[HP_Cuda]

Tommy - have you had timing issues before this six pack carb issue came to be?

Kinda crazy it jumps from 1600 > 600 > 1000rpm and the choke is disabled so 
Possibly the outboards are not closed at idle hence adding to the fun.

Found this with Promax adjustable plates which looks pretty sweet:
http://www.moparmusclemagazine.com/techarticles/mopp_0801_mopar_six_pack_tuning/

[scarpent1]

Tommy,
Did you ever fix or get a new regulator and set your fuel pressure to 6 psi or less?  The thread has been interesting to read.  I have dealt with similar problems on 4bbl but never worked with a 6 pack.

[tommyg29]

No, I never did anything with the fuel pump. Still reads just a tick under 7psi.

[tommyg29]

Pictures of the area where I disconnected the choke system. Could something here be contributing to my problems?
Idle is very inconsistent, and it still wants to just up and quit after running for about 7-8 minutes. I can be driving it around, and then it will just cough and quit, and not want to start again for at least 5 minutes.
Bowl levels are all right about the bottom of the hole.

[tommyg29]

Why the holes in the secondary throttle plates but not the main? and what is the purpose of those holes...just allowing a little more air?