choke - Pontiac GTO Forum
User Tag List

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 10-07-2011, 07:21 PM Thread Starter
RIP (12/27/60-7/18/15)
 
Topkat's Avatar
 
Join Date: Sep 2010
Posts: 767
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
choke

HI gang
I hooked up 12vdc to my electric choke and ran the car.
from pre start up thru a 10 minute idle, neither plate changed position.
the shaft on the dashpot(?) did pull all the way in but nothing up top moved
it seemed that the dashpot was keeping the secondary plate in the rear closed

What exactly is SUPPOSED to happen?
are both plates supposed to open?
thanks as always
Attached Thumbnails
Click image for larger version

Name:	DSCN3975.JPG
Views:	238
Size:	1.16 MB
ID:	12467  

Last edited by Topkat; 10-07-2011 at 08:44 PM.
Topkat is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 10-07-2011, 08:25 PM
 
Join Date: Nov 2009
Posts: 475
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Topkat View Post
HI gang
I hooked up 12vdc to my electric choke and ran the car.
from pre start up thru a 10 minute idle, neither plate changed position.
the shaft on the dashpot(?) did pull all the way in but nothing up top moved
What exactly is SUPPOSED to happen?
thanks as always
did the choke element get hot? the choke should be adjusted so it is just closed cold. then when you start the car the vacuum dashpot takes over and opens the choke just enough to get a rich fast idle. then the electric element slowly heats the choke spring up and opens the choke all the way.
freethinker is offline  
post #3 of 12 (permalink) Old 10-07-2011, 11:07 PM
 
likethat's Avatar
 
Join Date: Oct 2007
Location: Dayton, Oh and St. Louis, Mo.
Posts: 686
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I see full open choke and the ability for the secondaries to open. The smaller one toward the front of the engine is to open from the electric choke. That is one nice looking carb!

66 GTO 4bbl power windows A/C auto
67 GTO H.O. Convert 4spd
likethat is offline  
 
post #4 of 12 (permalink) Old 10-08-2011, 12:53 AM
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
Hey TK, looking at your photo and reading your description, I think there might be some confusion about what all those parts are. I think the 'dashpot' you're referring to (near the right in the photo, on the front of the carb) is actually the secondary vacuum pulloff - it's got nothing to do with a choke. There's not a choke on the secondaries --- only on the primaries, and in the photo it's already fully open. The plates on top of the secondaries are actually the secondary airvalve - they're supposed to be closed all the time unless the engine is running, under load, and you've got your foot in it enough to open the secondaries. The purpose of the dashpot is to hold the secondary air valves closed most of the time, until you step on it --- when you do that, manifold vacuum drops to near zero and the vacuum inside that dashpot will bleed off through a calibrated orifice, relaxing that link that holds the air valves shut, and allow them to open. Since in the photo the motor isn't running, there's no vacuum on the pulloff so it's "relaxed" and not holding the airvalves shut. What's holding them shut is the air valved tension spring. They won't open unless the engine is running and "pulling" on them with enough air flow to overcome the spring tension and force them open. That's one of the cool things about a QJet - when everything's calibrated and adjusted right, those air valves are going to open just enough to allow the engine to get all the air it wants, but no more. That keeps air flow velocity high through the carb so that all of its various circuits work well.

Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
post #5 of 12 (permalink) Old 10-08-2011, 01:37 AM
 
likethat's Avatar
 
Join Date: Oct 2007
Location: Dayton, Oh and St. Louis, Mo.
Posts: 686
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Looks like 2 open ports on the backside of the carb also. Are they capped or plugged into anything when you are running the car with the air filter pan off?

66 GTO 4bbl power windows A/C auto
67 GTO H.O. Convert 4spd
likethat is offline  
post #6 of 12 (permalink) Old 10-08-2011, 07:36 AM Thread Starter
RIP (12/27/60-7/18/15)
 
Topkat's Avatar
 
Join Date: Sep 2010
Posts: 767
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
the 2open ports were that way when I got the carb and nothing goes to them.do I need to cap them.The stud you see is hollow and also a vac port
I get it about the rear one,but is the front one supposed to be closed when the motor is cold? and or when I first turn the key on?
out of the box ,and installed it was all the way closed, after first starting it, running or not, it has not moved. I was just out there and it's still wide open and didnt move when I turned the key.
it has 12vdc on it...what gives?

thanks you!
Topkat is offline  
post #7 of 12 (permalink) Old 10-08-2011, 10:04 AM
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
Quote:
Originally Posted by Topkat View Post
the 2open ports were that way when I got the carb and nothing goes to them.do I need to cap them.The stud you see is hollow and also a vac port
I get it about the rear one,but is the front one supposed to be closed when the motor is cold? and or when I first turn the key on?
out of the box ,and installed it was all the way closed, after first starting it, running or not, it has not moved. I was just out there and it's still wide open and didnt move when I turned the key.
it has 12vdc on it...what gives?

thanks you!
Normally once they open, they won't close again - even with a cold engine - until you step on the throttle and release it. It's because the throttle stop screw that's sitting on the fast idle cam is holding the choke in position. When you step on it, it moves the screw off the cam and lets the mechanism move. Try that - see what happens. If it still doesn't close, Sum-Ting-Wong --- look for problems around the fast idle cam linkage.

Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
post #8 of 12 (permalink) Old 10-08-2011, 04:32 PM
 
likethat's Avatar
 
Join Date: Oct 2007
Location: Dayton, Oh and St. Louis, Mo.
Posts: 686
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would cap all unused ports.

66 GTO 4bbl power windows A/C auto
67 GTO H.O. Convert 4spd
likethat is offline  
post #9 of 12 (permalink) Old 10-08-2011, 05:27 PM
 
Join Date: Oct 2007
Location: Long Island NY
Posts: 4,702
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Garage




Eric Animal is offline  
post #10 of 12 (permalink) Old 10-08-2011, 06:55 PM
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
So would I.

BearGFR
Springtown, TEXAS
BearGFR is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO General Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
elect. choke Topkat 1964-1974 Tempest, Lemans & GTO General Discussion 7 10-07-2011 11:09 PM
carb choke linkage Topkat 1964-1974 Tempest, Lemans & GTO General Discussion 2 03-02-2011 11:20 PM
67 lemans 2bbl electirc choke? bnichols04 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 7 09-06-2007 09:03 PM
Choke problem? 66_goat 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 21 06-07-2007 09:21 PM
heat choke quest my1971gto4spd 1964-1974 Tempest, Lemans & GTO General Discussion 7 04-13-2006 07:34 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome