Quadrajet Problems - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 04-14-2014, 12:14 PM Thread Starter
 
Join Date: Apr 2014
Location: Ft. Worth, TX
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quadrajet Problems

I am currently working on restoring a 1967 GTO with my dad. We rebuilt the quadrajet, but we put it on there and it'll start up, but it won't keep running unless I mash on the gas. Eventually it just dies. So can anyone help me? I have read these forums enough to know that the q-jet is the best option but we may have to revert to an edlebrock due to lack of knowledge. Tips, advice, diagnosis, anything is appreciated. Thank you
Michaellopezzz is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 04-14-2014, 12:33 PM Thread Starter
 
Join Date: Apr 2014
Location: Ft. Worth, TX
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
By the way it's an automatic if that matters stock 400 engine
Michaellopezzz is offline  
post #3 of 8 (permalink) Old 04-14-2014, 01:10 PM
 
chuckha62's Avatar
 
Join Date: Apr 2010
Location: NorCal
Posts: 711
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Going to need much more information... there are a few things that come to mind... first, did you set the float levels correctly? Check your float level. If it's too low, it won't run and if it's too high, it will flood and die. Next, did you index the air screws? Turn them in til they seat and then back them out a turn and a half as a start point (usually VERY close). Then, set your idle speed screw. Turn it til it just touches the linkage arm, then turn it in a turn to a turn and a half.

This all assumes that everything else was done correctly when you rebuilt the carb. Did you soak it in carb cleaner over night? Did you rinse with good solvent afterwards, did you blow out all passages? There is SO much to rebuilding a quadrajet (or any carb) in order to make them run correctly.

Chuck

OH... since it's a '67... make sure the base gasket is installed correctly! If it's upside down, it will open up a passage to the atmosphere and run like crap!

When the only tool in your toolbox is a hammer, you tend to see every problem as a nail.

Last edited by chuckha62; 04-15-2014 at 12:21 PM. Reason: fixed multiple typos. DOH!
chuckha62 is offline  
 
post #4 of 8 (permalink) Old 04-14-2014, 06:14 PM
 
jmt455's Avatar
 
Join Date: Mar 2012
Location: SE Michigan
Posts: 725
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If it won't idle, but it will run with the throttle held open, you probably have plugged idle circuits, a huge vacuum leak or a combination of both.

Did you make sure the idle circuits and all other passages were completely clean when you cleaned out the carb? If you didn't remove the pressed-in plugs and completely clean out all the internal passages, you will probably need to go through the carb again.

First, make sure there are no open vacuum ports and all vacuum lines are correctly connected and in good condition.

1968 Pontiac GTO
1983 Pontiac Bonneville (G) wagon
2008 Pontiac G8 base
jmt455 is offline  
post #5 of 8 (permalink) Old 04-14-2014, 06:54 PM
Former Moderator
 
ALKYGTO's Avatar
 
Join Date: Mar 2010
Location: Wentzville, Mo.
Posts: 2,893
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 15 Post(s)
Garage

Good tips and OP don't give up on that Q-jet! They are far superior to the Edelbrock carb. If you do give up PM me and I'll take that Q-jet off your hands.....
ALKYGTO is offline  
post #6 of 8 (permalink) Old 04-14-2014, 07:48 PM Thread Starter
 
Join Date: Apr 2014
Location: Ft. Worth, TX
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks for all of the help, gonna work on it tomorrow
Michaellopezzz is offline  
post #7 of 8 (permalink) Old 04-15-2014, 11:31 AM
 
68GTO4004Spd's Avatar
 
Join Date: Jun 2008
Location: Columbus, OH
Posts: 659
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 1 Post(s)
Did you replace the fuel pump, the diaphragm goes bad over the years. Also don't get a pump that puts out more that 5 or 6 psi. As mentioned above, check for vacuum leaks.
68GTO4004Spd is offline  
post #8 of 8 (permalink) Old 04-16-2014, 12:09 PM
64-67 Expert
 
geeteeohguy's Avatar
 
Join Date: Feb 2008
Location: Fresno, California
Posts: 8,543
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
The '67 has a one year only carb, intake, and heat shield set-up. You must have the stainless steel heat shield under the carb to prevent the exhaust heat passage from superheating the carb. I use two base gaskets, with the steel plate sandwiched between them. Q-jet is a great carb, but very easy to mess up if you aren't aware of what you are doing 100%. Verify no vacuum leaks, and verify proper float level and fuel mixture, as stated.
geeteeohguy is online now  
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
Quadrajet FlambeauHO 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 9 01-10-2013 11:45 AM
Quadrajet problems jigaway 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 11 03-11-2012 12:24 PM
Cold start problems with rochester quadrajet. Fuel draining out of carb ? dillon14 1964-1974 Tempest, Lemans & GTO General Discussion 8 07-15-2011 10:55 PM
Quadrajet lazlo Intake and Exhaust Discussions 2 11-17-2007 08:40 PM

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