Quadrajet Question - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-26-2008, 09:22 PM
super_silent's Avatar
Member
 
Last photo:
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 127
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quadrajet Question

Hello everyone,

I have a 67 chevelle with a 327/275 hp, I just bought the car and when I'm driving and push the accelerator all the way the floor the car starts to hesitate and stumble once the secondaries open up, it almost feels like it's starving for fuel. I let off and it goes back to normal. I have another rebuilt Q-jet in a box , (I tried it once on my camaro but it had a stumble when accelerating from a stop) I and I put that on the car and it seemed to correct the hesitation at higher rpm's but it stumbled off the line. anyone have any ideas what may be causing this and how I might correct it ??


Thanks in advance

    Advertisement

Last edited by super_silent; 05-26-2008 at 09:46 PM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-26-2008, 09:53 PM
F&J F&J is offline
Registered User
 

Last journal entry: 32 Ford cabriolet conversion/windshield
Last photo:
Join Date: Mar 2007
Location: Connecticut
Age: 62
Posts: 1,571
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
The Chevelle carb might have dirty metering rods/jets in the secondaries.

That's if you did all the normal tune-up stuff plus timing, etc.


The rebuilt carb on the Camaro sounds like the accelerator pump or nozzles are not working.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-26-2008, 09:56 PM
super_silent's Avatar
Member
 
Last photo:
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 127
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
the car has new Bosch plugs, new wires, timing is set at 14 degrees.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-26-2008, 10:19 PM
Registered User
 

Last journal entry: more sheet metal stuff
Last photo:
Join Date: Mar 2008
Location: Salem, Oregon
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sounds like your secondary air valve is opening to fast. there is an adjustment for it located on the passenger side of the carb where the linkage connects to the secondary air valve. kinda hard to describe without showing you
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-26-2008, 10:22 PM
super_silent's Avatar
Member
 
Last photo:
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 127
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I thought that as well and tried checking if they were too loose but they don't appear to be.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-27-2008, 03:49 AM
curtis73's Avatar
Hates: Liver. Loves: Diesel
 
Last wiki edit: How to find cheap parts
Last journal entry: 1999-2001: Getting it on the road
Last photo:
Join Date: Dec 2005
Location: Carlisle, PA
Age: 40
Posts: 5,146
Wiki Edits: 16

Thanks: 0
Thanked 4 Times in 4 Posts
There is a little spring that slows the opening of the secondary air doors. Over time it weakens. On the passenger side there should be an allen screw and a flathead set screw. Adjust that spring a turn or two tighter and I almost guarantee you problem will dissapear.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-27-2008, 08:11 AM
Jmark's Avatar
Registered User
 
Last photo:
Join Date: Sep 2003
Location: phoenix
Age: 61
Posts: 4,815
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Here is the allen screw and adjusting (slotted) screw that Curtis mentions. Personally, I like to make very very small changes in the spring tension, maybe 1/8th turn at a time. If it ends up too tight, not only will it open way too late, if at all, but will act like a closed choke and cause it to go way rich.



Mark
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-27-2008, 08:31 AM
super_silent's Avatar
Member
 
Last photo:
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 127
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks very much to everyone for all the input, I will make the adjustment later this afternoon and post results.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-27-2008, 08:36 AM
malc's Avatar
Living At The Speed Of Life
 
Last photo:
Join Date: Jun 2003
Location: Espaņa Right Coast
Posts: 3,261
Wiki Edits: 0

Thanks: 90
Thanked 94 Times in 80 Posts
Here it is in words at
thirdgen.org.Itīs the same for regular and computer controlled carbs.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-27-2008, 08:08 PM
super_silent's Avatar
Member
 
Last photo:
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 127
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Problem solved. I swapped out the metering rods with the other Qjet I have here and re-adjusted the secondary air doors....no more bogging ! Thanks again to everyone for all the great info.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
supercharger.... 73monte Engine 16 07-24-2010 10:27 AM
Quadrajet question Speakrdude Engine 10 10-25-2009 01:16 PM
Quadrajet rebuild question? Shefron Engine 14 11-13-2005 11:01 PM
Ignotion Set-ups Native Gearhead Engine 8 11-29-2003 01:20 PM
Hi All I just Joined, Questions Re:454 rebuild Gay-Shark Engine 8 11-29-2003 10:25 AM


All times are GMT -6. The time now is 03:02 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.