q-jet tuning - 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 01-15-2009, 08:40 AM
Registered User
 
Join Date: Jan 2009
Location: Illinois
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
q-jet tuning

I recently purchased a 1980 k20 with a recently rebuilt oem q-jet carb. During rebuild the previous owner installed a manual choke. It runs great once it warms up, but during initial start up when it's cold it seems to not fire and then floods out very easily. Does anyone have any adjustment tips that could solve this problem?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-15-2009, 10:26 AM
Registered User
 
Last photo:
Join Date: Jul 2007
Location: Cincinnati
Age: 38
Posts: 183
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
How are you applying the choke? Are you just pulling the knob out, or are you pushing the pedal to the floor and then pulling on the knob? This can make a difference since - in stock form - the driver pushes the pedal to the floor in order to engage the choke. What this does is squirts a load of fuel into the intake (to help richen the mixture), but it also engages the fast-idle linkage which helps in initial startup and in keeping it running while still cold. Not having the fast-idle engaged (or setup correctly) would cause a lot of problems in trying to get it to start.

If that doesn't help, then maybe the fast idle hasn't been set correctly, or a part might have been left out if it didn't seem important.

Also - another thought - is if the original choke was vacuum operated, then the rebuilder might not have blocked the vacuum port to the choke housing. If there is an inverted-flare nipple on the choke housing (usually on top, pointing towards the back), then it was vacuum operated and the port might have to be plugged. Of course, the port that needs to be plugged is internal, so you will have to remove the choke housing from the carb body - the vacuum port is a small hole (about 1/16") in one of the choke mounting posts. Plug this hole with some J.B. Weld, or some lead (pieces of lead fishing weights work well) and then re-assemble the choke and you might be good to go.
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
Carb Tuning Input/Thoughts (blower) camaroman7d Engine 20 12-16-2008 02:22 PM
holley tuning A/F power valve and jet tomthecomic Engine 2 05-20-2008 12:36 AM
Tuning 2 Demon Carbs on a Hemi steve392 Engine 0 03-26-2007 01:17 PM
Demon Tuning by cuda66273.... mstngjoe Engine 4 03-13-2006 06:46 AM
what first? advance curve or carb tuning? dirtydave Engine 3 11-07-2003 04:42 PM


All times are GMT -6. The time now is 03:22 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.