Register now to get rid of these ads!

Featured Technical Got her to start but won’t idle

Discussion in 'The Hokey Ass Message Board' started by Christie, Jun 6, 2020.

  1. Flat Roy
    Joined: Nov 23, 2007
    Posts: 403

    Flat Roy
    Member

    When I supercharged my 8BA I put a Q-Jet from a supercharged Buick on top of the blower. It had all the running symptoms yours has. I took it to a friend who builds nasty motors. He said it was starving for idle air. Opening the throttle plate more took it off of the idle system. Sooo solution was to drill very small hole in each plate and progressively make them bigger until it idled. It worked great. You might want to check with some one local who knows before you try this.
     
  2. ^^^^^ No No No. Not on a stock engine.
     
  3. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 2,344

    2OLD2FAST
    Member
    from illinois

    Excellent way to turn a perfectly good carburetor into a paperweight !
     
  4. Truck64
    Joined: Oct 18, 2015
    Posts: 4,056

    Truck64
    Member
    from Ioway

    A vacuum gauge needs to be connected to a constant source of manifold vacuum. It's a little trickier to do because stock or factory style carburetors don't have this.

    There is a silver pipe plug right in front of the carburetor in your picture, pointing at an angle. That is a convenient place to connect a mechanic's vacuum gauge, need a 3/8" NPT fitting with a barbed end.

    You really need to find a blockhead closer to you to help out.
     
    Christie likes this.
  5. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

    Omg, ty!!!! I was wondering if I could use one of those plugs! And nah, I wanna do it myself and you guys are a HUGE help as it is !


    Sent from my iPhone using The H.A.M.B. mobile app
     
    David Gersic and Desoto291Hemi like this.
  6. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

     
  7. treb11
    Joined: Jan 21, 2006
    Posts: 3,455

    treb11
    ALLIANCE MEMBER

    Can't offer anything more than the (excellent) advice offered so far.
    Just wanted to say I admire that you are sticking to working on your project. I think everyone might like to see pics of the whole car

    Sent from my SM-G965U using The H.A.M.B. mobile app
     
    Desoto291Hemi and VANDENPLAS like this.
  8. 37 caddy
    Joined: Mar 4, 2010
    Posts: 322

    37 caddy
    Member
    from PEI Canada

    I think it is a vacuum leak,check the hoses and ports,they wont idle with a leak.check for any loose bolts or plugs,it is something simple,keep trying.Dont modify anything yet. harvey
     
  9. Moriarity
    Joined: Apr 11, 2001
    Posts: 18,086

    Moriarity
    SUPER MODERATOR
    Staff Member

    I have already said it a couple of times. The threaded port sticking down from the choke assembly. This will leak vacuum if there is nothing hooked to it and it looks like there is nothing hooked up to it. have someone hold their finger over the opening while you start it or put a piece of tape or a rubber hose with a bolt in the end of it... anything to plug it
     
  10. dan griffin
    Joined: Dec 25, 2009
    Posts: 468

    dan griffin
    Member

    Not all Qjets are created equal. A lean idle makes for less emissions ( smog). On about 73 and up Qjets the factory enlarged the air bleed orifice and
    put in a air by pass under the throttle plates. with this set up backing out the idle screws makes no difference. THE fix is a small dia. piece of copper wire bent in a horse shoe shape inserted into the air bleed hole, the air bypass hole in the throttle plate can be plugged with a accelerator pump check ball. These mods will richen up the idle circuit.
     
    Christie likes this.
  11. F-ONE
    Joined: Mar 27, 2008
    Posts: 2,105

    F-ONE
    Member
    from Alabama

    That’s not the best vacuum source. The spark port off the carburetor to the distributor is metered ...it’s all part of that Loadomatic advance system.

    A better vacuum source is off the intake below the carburetor base. This is manifold vacuum that runs the wipers.
    It’s that way in an 8BA but Y blocks should be the same.

    The bottom line...
    Your not going to get a good vacuum signal off that location for your gauge.

    You have bigger fish to fry.

    What’s the history of the carburetor? Remanufactured....When?
    Do you know what vehicle it’s from? There’s hundreds of applications for a 94.
    Do you still have the original carburetor?

    I may be wrong here on a 94. The info about the heat choke below is based on later 2100s, Holley 1850s and 4100s.

    I can’t see how the heat choke can cause a vacuum leak unless it’s pulling through the screws in the carburetor body. The heat choke is a stand alone unit that screws to the side of the carburetor. It should not draw vacuum. As a matter of fact, if anything you might have an exhaust leak off the exhaust manifold if equipped with the heat tube rather than a vacuum leak from the carburetor. That is unless it’s pulling through the mounting screws which is unlikely.

    I know I may sound like a broken record but check that carburetor base. I was wrong about my Flathead having 3 gaskets under the old carburetor. It had 4, I found another stuck the the bottom of the old carburetor.
     
    Christie and gimpyshotrods like this.
  12. dan griffin
    Joined: Dec 25, 2009
    Posts: 468

    dan griffin
    Member

    You are right,nothing I am on wrong page. My wife wife keeps telling me that I am not yery smart.
     
  13. Moriarity
    Joined: Apr 11, 2001
    Posts: 18,086

    Moriarity
    SUPER MODERATOR
    Staff Member


    There is an internal passage in the carb that puts vacuum in the choke housing. The vacuum is how the heat from the tube is drawn up there
     
  14. Moriarity
    Joined: Apr 11, 2001
    Posts: 18,086

    Moriarity
    SUPER MODERATOR
    Staff Member

    here is a pic of one of those carbs, see the gasket between the choke housing and the carb body? that is because there is a vacuum passage there. click the pic to enlarge. She needs to check the threaded fitting coming out of the bottom of the choke housing for a vacuum leak

    94carb.jpg
     
    Desoto291Hemi likes this.
  15. Mr. Mark,,,,,( Moriarity ) ,,,is right on the money,,,,as usual !

    Tommy
     
    F-ONE likes this.
  16. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 24,916

    Jalopy Joker
    Member

    since car not really running yet this may have no affect but, have the correct vented gas cap? 20200608_134311.jpg 20200608_134323.jpg
     
  17. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

    It is plugged, I had plugged it before in there to block the passageway and I did notice that the whistling sound that would periodically happen disappeared but it still didn’t fix the problem of not holding the idle


    Sent from my iPhone using The H.A.M.B. mobile app
     
    Moriarity likes this.
  18. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

    I also managed to get someone to press on the pedal to keep her Idling while I adjusted the idle screw and the mixture screws and doing those things didn’t even help the issue she still peters out after a while


    Sent from my iPhone using The H.A.M.B. mobile app
     
  19. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

  20. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

    IMG_0114.JPG IMG_4701.JPG IMG_8038.JPG IMG_8728.JPG IMG_8727.JPG

    I did the upholstery, not perfect, but first time doing it.



    Sent from my iPhone using The H.A.M.B. mobile app
     
  21. saltflats
    Joined: Aug 14, 2007
    Posts: 10,078

    saltflats
    Member
    from Missouri

    Can you turn the idle screw in more, how about a picture of the carburetor side views.
    How many turns are the idle mixture screws out?
    If you put your hand over the carburetor when it is running, does it get better or worst?
     
  22. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

    Idle mixture screws are 1 and 1/4 out each. I’ll take pics and post later. Also, she revs when I cover the top of carb with my hand


    Sent from my iPhone using The H.A.M.B. mobile app
     
  23. Christie
    Joined: Jun 4, 2007
    Posts: 187

    Christie
    Member

    61077043181__F7C51E78-A8E5-47B2-A750-235BF311DC99.JPG 61077043181__F7C51E78-A8E5-47B2-A750-235BF311DC99.JPG





    Sent from my iPhone using The H.A.M.B. mobile app
     
  24. saltflats
    Joined: Aug 14, 2007
    Posts: 10,078

    saltflats
    Member
    from Missouri

    Hard to tell but it looks like the idle speed screw is not touching anything, am I wrong?
    Sounds like the idle dash pod is working but not the idle screw.
     
  25. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 24,916

    Jalopy Joker
    Member

    have you looked at distributor points gap/condition? - not problem but, large hose from back of carb to distrib too large of diam - hose from fuel pump to carb 5/16"?
     
  26. F-ONE
    Joined: Mar 27, 2008
    Posts: 2,105

    F-ONE
    Member
    from Alabama

    I see says the blind man.
     
  27. 67L36Driver
    Joined: Jun 1, 2020
    Posts: 67

    67L36Driver

    What goes here?
    [​IMG]
    Looks like a power brake booster port.

    But, I don’t know squat about ‘Y’ block Fords.


    Sent from my iPhone using Tapatalk
     
    mcsfabrication and saltflats like this.
  28. AngleDrive
    Joined: Mar 9, 2006
    Posts: 767

    AngleDrive
    ALLIANCE MEMBER
    from Florida

    Looks to me like you adjust the idle with the dash pot
     
  29. Blues4U
    Joined: Oct 1, 2015
    Posts: 4,669

    Blues4U
    Member
    from So Cal

    Dash pots are just used to slow the return of the linkage to idle, kind of like a shock absorber for the throttle linkage. The idle speed would still need to be set by the idle speed adjustment screw, and I agree with @saltflats , it doesn't look like the idle screw is touching anything. But my eyes aren't so good, so maybe that's not right.
     
  30. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 5,034

    Ebbsspeed
    ALLIANCE MEMBER

    It looks like the fast idle cam and linkage that is activated by the choke is missing from the passenger side of the carb. Since it is missing, there is nothing for the idle speed screw to bear against.
     
    Lost in the Fifties and ottoman like this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.