Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Your Choice of Carb?

  1. #1
    Join Date
    Jan 2004
    Location
    Washington State
    Posts
    1,652

    Default Your Choice of Carb?

    My engine came with a quadrajet. Not sure if it is a stock one, although I don't think so. It starts up great, idles great, choke works. While driving and trying to pull a hill it bogs out and won't go into the secondaries, and has stack fired a couple of times. Should I take it out and go through it with a complete overhaul or rebuild kit or should I try something else? Just want everyones opinions. I'm not partial to any one carb, just want one that works good. Wouldn't mind keeping mine if it can be fixed. Carbuerator is installed on a 1969 buick 350. Thanks Everyone

  2. #2

    Default

    I would rebuild it or get another q-jet to replace it. They are good offroad carbs. Next option would be to get a Howell FI conversion. Now that would be the cat's pajamas.

  3. #3
    Join Date
    Jul 2007
    Location
    Rhoadesville, Virginia (five miles from no place)
    Posts
    5,125

    Default

    I did a Holley Throttle Body kit on my 396 and wouldn't dream of going back to a carb. No idle issues, immediate response, excellent cold start, etc, etc.....

    All that said, your Quadrajet should be evaluated before you attempt a rebuild. Be sure the choke housing isn't worn out where the shaft runs through it. They are about 80 bucks new alone. Likewise for the throttle shafts. If they are worn, the carb is junk.

    The major problems in the Quadrajet are a couple of things:

    Generally if they are dirty and the primary metering rods are stuck, they will hesitate and run poorly.

    Same if the accelerator pump cup is shrunken or worn.

    If the choke is not opening fully, or the choke pulloff isn't operating correctly, the limiter will prevent the secondary air flaps from opening at all and render the secondaries inoperative. If the rear or secondary flaps on top are sticking, the secondaries won't operate either. The rear air flap on top lifts the metering rods for the secondaries to open the secondary jets and allow fuel into the secondary venturies.

    Also be sure there are no vacuum leaks, timing issues, or other things causing your problem first.
    "Free advice is worth what you pay for it."™

  4. #4

    Default

    I went down to Ky Outback before out Local FE there with some guys from Mi. One of the guys was JZOliver. He had a 350 in his 715 and it impressed me how well it handled the hills and off camber stuff. I am in the process of getting my driveline ready to go in. I sent him a pm and asked what he was using, this is his answer, I will go this route.

    "I'm running an Edelbrock performer 600, with offroad needles and seats. Holley and Edelbrock both make an offroad version of there carbs that work pretty well from what I've heard. My buddy Kevin runs a Holley Truck avenger on his 350 and it works a bit better than mine I think, allowing him to start his at more angle and it stalls a little less than mine."
    "We are here for the meeting!"

  5. #5
    Join Date
    Dec 2003
    Location
    Giddings, Texas
    Posts
    7,729

    Default

    EFI is my suggestion.

    I have an Edelbrock 600 on the 396. I added the off road needles and seats. I also got the jet/rod tuning kit. I am still playing with all the different combinations. No matter the combination, it does good on side angles but wants to flood out on really steep up hill climbs. I have learned that as long as I am at at least 2200 rpm, it will burble some, but not stall. Matter of fact, the burble causes me to mash a little more and then we rocket up whatever we are climbing. It took me a lot of not climbed hills at the '06 FE to figure that out though. I get 12-13 mpg highway with it.

    Spicer put a Holley off road carb on Velvet for his TTC driving. He said it did just as good as the guys with EFI. But, drinks gas fast.

    With fuel cost the way they are, it is almost cost justified to start out with EFI. Figure 9-10 mpg from the Q-Jet since that is what I got on the 396 when I still had one on it. EFI will give you probably a minimum of 10% better. Call it 1 mile per gallon more. Or about 28 more miles per tank. Which is almost 3 gallons savings per tank or $10-$12. Add in the off road prowess, starting ease and hands off dependability for years and EFI looks pretty good to me.
    Remember if you didn't build it you can't call it yours.

    6.2 powered M715, 5 M1009's, M416, 2 M101's, 2 M105's, 3 M35's, M1007 6.5 turbo Suburban project called Cowdog.

    https://www.youtube.com/channel/UCCz...HGkBCfhXZ5iuaw

  6. #6

    Default

    My brother put a howell efi on his early bronco and is working on his second conversion now. With unlimited $$ EFI would be my first choice however, budget considerations would make a new (rebuilt) carb my choice. I don't think I would spend the $ to get the carb rebuilt unless the guy rebuilding it knows what he is doing and will install and tune it after rebuilding it. Carb's are more and more a lost art.

  7. #7
    Join Date
    Jan 2007
    Location
    Fort Smith, Arkansas
    Posts
    911

    Default

    I'm not a carb expert and hate allways have to jack with them. Mine is a Holley 600 on a chevy 350. It runs well for now but doesn't idle quite right yet. I replaced another holley with this one that ran great until I sucked it full of garbage. Before that was a Q-jet for a couple years that was so-so. I'd go with fuel injection if the budget allows.

  8. #8

    Default

    You have a good carb Todd. Rochesters are great but like any other need tweaking. I have a replacement if yours is TU. We have spent very little time on it so I'm sure we can make it better. We will "chat"....
    Liz, covid, murdered 10/19/21

  9. #9
    Join Date
    Jul 2007
    Location
    Rhoadesville, Virginia (five miles from no place)
    Posts
    5,125

    Default

    Quote Originally Posted by kwai View Post
    I don't think I would spend the $ to get the carb rebuilt unless the guy rebuilding it knows what he is doing and will install and tune it after rebuilding it. Carb's are more and more a lost art.
    Smart advice. I have seen more damage done by the installer than the rebuilder at times. Of course I have seen it the other way too!

    Carburetors aren't mystery boxes or rocket science, but they need to be right. Clean, not half-worn-out, and adjusted to the application.

    Paying another to rebuild one these days requires finding the person who can do it, then paying what it costs. Many times its cheaper to replace rather than rebuild. A reman Q-jet now runs around $400....
    "Free advice is worth what you pay for it."™

  10. #10

    Default

    If you don't have money for EFI then keep the Q-jet. They are pretty good carbs and get decent mileage if you keep your foot out of it. Choke pulloff going bad is a fairly common problem. The pulloff is on the right front of the carb with a short vacuum line going to a port on the carb near the fuel inlet. If it has a secondary pulloff its on the back right of the carb. Take a short section of vacuum line, hook to the choke pulloff and suck on it. You should see the rod coming out of the end of the pulloff move. If you suck on it and it doesn't move or you keep having to suck hard to make it move just a little then it needs a new pulloff. You can test the secondary the same way. You don't have to pull the carb off to test the pull offs or to replace them. Check your fuel pressure and volume too before you condemn the carb and the filter. If you were closer I could rebuild the carb for you, I've done a few. I don't like rebuilding them without being able to tune them on the rig afterwards though.

Similar Threads

  1. Another rim choice for Rockwells
    By blazen71 in forum Modified Tech
    Replies: 9
    Last Post: December 17th, 2009, 10:28 PM
  2. Holley 4bl Carb, AMC 360 - Carb rebuild time?
    By BubbaWilkins in forum Modified Tech
    Replies: 8
    Last Post: July 6th, 2009, 11:54 AM
  3. If you had the choice... 523 Ford or 502 Chevy?
    By P|n_BaLL in forum Modified Tech Archives
    Replies: 18
    Last Post: May 6th, 2004, 11:30 PM
  4. Motor choice-
    By Brian Sisson in forum Open Discussion Archives
    Replies: 22
    Last Post: January 30th, 2004, 05:47 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Site Upgrade, Design Modifications & Administrative Support by:
Palm River Enterprises LLC, IT Solutions
President: Tom King, User ID=teking
This site is owned and operated by:
M715 Zone, LLC
President: Jon Schmidt, User ID=brute4c


If you have any suggestions, comments, problems or questions, contact:  brute4c@m715zone.com
Use of this site means you understand and agree to our TERMS OF USE

Copyright Notice:
This web site is subject to the protection of the copyright laws of the United States and other countries. Except for Personal Use Only, you may not modify, copy, distribute, transmit, display, perform, reproduce, publish, license, create derivative works from, transfer, or sell any information obtained from any part of the M715 Zone website without the prior written permission of M715 Zone, LLC. Written permission can only be obtained by contacting brute4c@m715zone.com

Copyright 1998-2024