Q-jet running rich,
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 899
Likes: 1
From: Kansas
Q-jet running rich,
Hi yall,I just replaced the spark plugs on the 73 they were all black, runs better now but it idles high and have turned idle screw down all the way,still high,and the mixture screws dont respond at all,
I plan on rebuilding it but thought Id get a little info on what the cause could be . Oh ya the choke is open so thats not it,timming is fine. Thanks J.
I plan on rebuilding it but thought Id get a little info on what the cause could be . Oh ya the choke is open so thats not it,timming is fine. Thanks J.
Le Mans Master
Joined: Feb 2001
Posts: 6,317
Likes: 289
From: Ocala FL
Originally Posted by vetteaddic
Hi yall,I just replaced the spark plugs on the 73 they were all black, runs better now but it idles high and have turned idle screw down all the way,still high,and the mixture screws dont respond at all,
I plan on rebuilding it but thought Id get a little info on what the cause could be . Oh ya the choke is open so thats not it,timming is fine. Thanks J.
I plan on rebuilding it but thought Id get a little info on what the cause could be . Oh ya the choke is open so thats not it,timming is fine. Thanks J.
Symptoms:
- runs good cold
- exhaust is black at warm idle
- throttle response is good cold
- throttle response is poor (blogs) hot
- plugs black that normally run right
Borg-Warner makes a brass replacement float but I've lost the number. The composite float will probably last you 10 years or so, so a new composite one isn't the end of the world.
Intermediate
Joined: Oct 2004
Posts: 36
Likes: 0
From: NEW MEXICO
Addic,
I have had the same problem with my 73. With help from Lars and his papers I found the rods were not being pulled down far enough into the jets. This is one possibility assuming your carb has not been "bubba'd". I knew mine was set up original.
Good Luck
I have had the same problem with my 73. With help from Lars and his papers I found the rods were not being pulled down far enough into the jets. This is one possibility assuming your carb has not been "bubba'd". I knew mine was set up original.
Good Luck
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Originally Posted by 4ME+N73
Addic,
I have had the same problem with my 73. With help from Lars and his papers I found the rods were not being pulled down far enough into the jets. This is one possibility assuming your carb has not been "bubba'd". I knew mine was set up original.
Good Luck
I have had the same problem with my 73. With help from Lars and his papers I found the rods were not being pulled down far enough into the jets. This is one possibility assuming your carb has not been "bubba'd". I knew mine was set up original.
Good Luck
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 899
Likes: 1
From: Kansas
Took the carb apart and seen that it has been rebuilt recently,has a new float,and needle,
Did see the front needle jets looked like the holder was a bit rusty were it sits in the brass peice and could have been binding,other than that looks good ,havent installed yet to see if problem persist.Thanks
Did see the front needle jets looked like the holder was a bit rusty were it sits in the brass peice and could have been binding,other than that looks good ,havent installed yet to see if problem persist.Thanks
Heel & Toe
Joined: Jan 2006
Posts: 17
Likes: 0
From: BAKERSFIELD CA
if the idle speed will not come down make sure the secondary throttle
plates are not stuck open,opening the air valve on the secondarys should not make a difference in the idle quality,if it does the throttle plates may not be sealed.lightly tapping on them with a screw stick may
seat them and help with the idle speed.
plates are not stuck open,opening the air valve on the secondarys should not make a difference in the idle quality,if it does the throttle plates may not be sealed.lightly tapping on them with a screw stick may
seat them and help with the idle speed.
Intermediate
Joined: Oct 2004
Posts: 36
Likes: 0
From: NEW MEXICO
Originally Posted by comp
why didn't they ??
I am not sure why. It was not the spring, they would not go in far enough with the spring removed. I wasn't sure how to remedy so i put an o ring under the jets and it made all the difference. I believed it has run rich since new (this is the original carb and set up). Although, back in the leaded fuel days the pipes ran nice & clean on long hauls.
