'72 Quadrajet Question (stop yawning!!) - NCRS Discussion Boards

'72 Quadrajet Question (stop yawning!!)

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Wendell Allen

    '72 Quadrajet Question (stop yawning!!)

    Hi All.........

    In my more ignorant pre-NCRS days, I purchased a rebuilt Quadrajet for my base model, automatic equipped, '72 from a local auto supply house. The carb came in a Holley box, and because of this, I assume it was rebuilt by them. But then again, there are so many companies outsourcing their work, I don't know for certain.

    The carb has had the infamous flat spot at WOT ever since I got the thing (No! don't hit the "back" button yet!). Other than that, the carb's fine. But I think I've bumped into something that will have an effect on the flat spot and I'd like to get your thoughts.

    Some of you are aware that I recently ripped into my dash to fix a myriad of wiring problems created by a previous owner. One of a number of things I found disconnected under the dash was the transmission detent switch that's activated by the accelerator when it's at WOT. According to the factory service manual, when this switch is activated it will cause the tranny to kick down one gear as long as the car is moving at less than 70 mph. Obviously, since it's been disconnected, it hasn't been kicking down the tranny like it's supposed to.

    What I'm wondering is, if I wire this switch back up, and assuming it works properly, could the drop in gears at WOT and resulting RPM increase bring enough air flow through the carb to suck enough gas from the intermediate and/or primary circuits to reduce, or hopefully, eliminate my beloved flat spot?

    I really don't want to have to buy another carb until I can afford the $300 purchase price and $400 or what ever Jerry Luck's charging these days for a proper rebuild on a correctly numbered carb.

    Anyone have any experience with this?

    As Always - Thanks,

    Wendell
  • Michael W.
    Expired
    • April 1, 1997
    • 4290

    #2
    No yawning here- this is the only interesting

    question on the board. I go snoozy with all the mid-weird and scrape axle stuff

    Have you tried adjusting the spring tension that holds the upper plate on the secondaries shut? If the spring has too little tension, you will get a huge flat spot when you got WOT. If you have too much spring tension, the plate may not open under all conditions, and give no flow through the secondaries.

    My small block '73 suffered from the blahs for years with this, Rolph Kreuger set me straight.

    Comment

    • Chuck S.
      Expired
      • April 1, 1992
      • 4668

      #3
      Re: '72 Quadrajet Question (stop yawning!!)

      Wendell,

      I think you are on to something. Mike's advice may be applicable as well, but I expect getting your THM kick-down switch working would go a LONG WAYS toward eliminating your "flat spot".

      That's probably why the General put it there in the first place...to "six" the "flat spot". The thing is, I can't understand why anyone owning a Corvette would WANT TO disconnect the switch. Good luck on not finding more related problems.

      Chuck Sangerhausen

      Comment

      • Wendell Allen

        #4
        Re: '72 Quadrajet Question (stop yawning!!)

        Chuck,

        So far, not counting what I've found loose in the engine compartment, I've discovered:

        6 unconnected terminals behind the instrument cluster

        4 wires sans terminals hanging loose

        1 missing seat belt thermal relay (what ever the heck that is)

        7, count 'em, 7 unconnected terminals under the center console

        2 wires, including the console ground, sans terminals hanging loose in the center console

        And NONE of these wires were for simple light bulbs. Frankly, I'm surprised this car even ran. But I sure am glad all you NCRS members talked me into buying the AIM and factory service manual when I first joined!!

        Regards, Wendell

        Comment

        Working...

        Debug Information

        Searching...Please wait.
        An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

        Please push the back button and reload the previous window.'
        An unexpected error was returned: 'Your submission could not be processed because the token has expired.

        Please push the back button and reload the previous window.'
        An internal error has occurred and the module cannot be displayed.
        There are no results that meet this criteria.
        Search Result for "|||"