Slant Six Forum
https://slantsix.org/forum/

Choke pull off and Fast Idle? Related??
https://slantsix.org/forum/viewtopic.php?t=47921		 Page 1 of 1
Author:  1966DartConvertible [ Wed Feb 15, 2012 5:31 pm ]
Post subject:  Choke pull off and Fast Idle? Related??
Hi

I have read the "choke-adjust" page here and also the Holley 1920 Manual here but still dont quiet understand how they work.

Correct me if im wrong. When i first turn the ignition key to start the engine, the vacuum created in the carb body pulls the choke pull off out. Correct?

What does this do? opens choke butterfly a little? and also pulls the fast idle cam up and set the fast idle screw on one of the fast idle cam steps? then what?

As the engine warms up, the choke pull off slowly releases and the idle speed goes down? But the fast idle cam is "seated" on one of the cam steps how can the speed go down?

Sorry if im confusing you more, im just trying to understand how this thing works as mine is NOT working! (or most probably not adjusted properly).

As you can see from this picture below, the "U" choke pull off link is way too "wide"... will be adjusting that this weekend hence need your help.

Image

PS: Yes Dan I know I should have bought the brand NEW carb of you... wink ;)

Thanks

Syed[/url]
Author:  Aggressive Ted [ Wed Feb 15, 2012 6:09 pm ]
Post subject: 
Quote:
But the fast idle cam is "seated"
That is great you posted a picture....

Looks like the engine is not running in this picture. If it was, the vaccuum pull off would have engaged dropping you back down to low idle.

Use, the "U" shape in the linkage is a little too wide for the vacuum pull off to pull it off the last fast idle position. You need to squeeze that a little till it drops off the last high idle step when warmed up.

How come the automatic choke linkage is not hooked up?
Author:  1966DartConvertible [ Wed Feb 15, 2012 6:24 pm ]
Post subject: 
Quote:

How come the automatic choke linkage is not hooked up?
Thats because I dont have one...

What is the function of the auto (remote) choke linkage? Pull the choke butterfly open when warmed? If so, then clearly I will need to get either the choke well or the electric choke upgrade posted in this site.

Syed
Author:  SlantSixDan [ Wed Feb 15, 2012 6:44 pm ]
Post subject: 
You need a choke thermostat and pushrod, either the original type or the electric type, or none of the rest of your questions are relevant. The choke thermostat pushes the choke closed (which also swings the fast-idle cam into position) so that the engine will start quickly from cold and keep running once it has started. Once the engine is running, manifold vacuum pulls the choke pull-off diaphragm and stem, which partially opens the choke so the engine can receive enough air to run.
Author:  1966DartConvertible [ Wed Feb 15, 2012 7:03 pm ]
Post subject: 
Quote:
You need a choke thermostat and pushrod, either the original type or the electric type, or none of the rest of your questions are relevant. The choke thermostat pushes the choke closed (which also swings the fast-idle cam into position) so that the engine will start quickly from cold and keep running once it has started. Once the engine is running, manifold vacuum pulls the choke pull-off diaphragm and stem, which partially opens the choke so the engine can receive enough air to run.
Thanks Dan, I knew im missing something.

Does this look like what I would need for my ''66 Holley 1bbl setup, Dan?

Here is a picture of my manifold
Image

Also, since the original well type choke thermostat is non-adjustable, wouldn't the use of thin/thick carb gasket affect the timing of the choke opening/closing?

Syed
Author:  SlantSixDan [ Wed Feb 15, 2012 7:19 pm ]
Post subject: 
Quote:
Does this look like what I would need for my ''66 Holley 1bbl setup, Dan?
Yes, but the price seems unreasonably high. Check with Old Car Parts Northwest and see if they have a Standard #CV42 choke thermostat for you.
Quote:
Also, since the original well type choke thermostat is non-adjustable
That's only true for the '73-up variety. The units up through '72, including the type you linked, are adjustable.
Quote:
wouldn't the use of thin/thick carb gasket affect the timing of the choke opening/closing?
It affects how strongly the choke is pushed closed for any given choke thermostat adjustment, yes.
Author:  1966DartConvertible [ Mon Feb 20, 2012 7:23 pm ]
Post subject: 
This looks more reasonably priced ($40). Should fit my '66 slant six?

http://www.ebay.com/itm/380146162511

Syed
Author:  SlantSixDan [ Mon Feb 20, 2012 7:58 pm ]
Post subject: 
The '63-'65 item can be modified to fit a '66 manifold. I'm not sure why I bother pointing you at likely good and reasonably priced sources for the right parts; you always seem to disregard me, so I'm gonna stop.
Author:  1966DartConvertible [ Mon Feb 20, 2012 9:00 pm ]
Post subject: 
Quote:
The '63-'65 item can be modified to fit a '66 manifold. I'm not sure why I bother pointing you at likely good and reasonably priced sources for the right parts; you always seem to disregard me, so I'm gonna stop.
Hi Dan,

I can't find the item in their find/search engine. So i shoot Ray an email and has not received a reply since. Of course I could have called him at international rate and spoke to him directly, but I did not.

Thanks for that link you gave earlier, your advice is greatly appreciated and without your help my slant six would not be running by now.

Syed
Author:  SlantSixDan [ Tue Feb 21, 2012 2:36 pm ]
Post subject: 
Just spoke to Ray on the phone. He's looking for your choke thermostat, almost certainly has it (I saw it when I was last at his shop). No reason to pay phone rates for international calls; get Skype!
Author:  1966DartConvertible [ Tue Feb 21, 2012 4:11 pm ]
Post subject: 
Quote:
Just spoke to Ray on the phone. He's looking for your choke thermostat, almost certainly has it (I saw it when I was last at his shop). No reason to pay phone rates for international calls; get Skype!
Thanks Dan, as always.

Syed
Author:  1966DartConvertible [ Tue Feb 21, 2012 6:54 pm ]
Post subject: 
Received email from Ray.

"Yes we have a new Holley CV-42 choke thermostat in stock. Cost $42.50 plus shipping. Thank you.

Ray"

Just like you said Dan, he is the cheapest. So far what I found on Ebay the cheapest is $64.99 (was $49.99).

Will order from him once I get the shipping quote to Malaysia.

Syed
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/