Register now to get rid of these ads!

Hot Rods 63 Impala new Edelbrock idle too high

Discussion in 'The Hokey Ass Message Board' started by Eth727, Nov 10, 2025 at 1:08 PM.

  1. Eth727
    Joined: Jun 20, 2024
    Posts: 327

    Eth727

    IMG_8738.jpeg IMG_8739.jpeg Hey guys I just installed a new Edelbrock 1403 with electric choke. I started it and it idles at 1200 . It should go down with the choke and it didn’t. It sat for a month before being started and today was 70 degrees. I didn’t mess with any of the adjustments until I get more advice. The choke is hooked up to keyed on + and grounded - at the screw housing.
     
  2. Oneball
    Joined: Jul 30, 2023
    Posts: 1,616

    Oneball
    Member

    The choke isn’t “on” it’s open and the fast idle screw is not on the fast idle cam. It’s purely at 1200rpm on the idle speed screw. If you want to reduce idle speed you need back out the idle screw. If you want the choke to work you need to adjust it related to engine/air temp.
     
    Last edited: Nov 10, 2025 at 1:55 PM
    Sharpone, Tim and Dos Cincos like this.
  3. Happydaze
    Joined: Aug 21, 2009
    Posts: 2,351

    Happydaze
    ALLIANCE MEMBER

    The screw in the top left of the first pic is the idle screw. Back that out some.

    And read the manual! Don't get hung up on 'tuning', well not yet anyway. Getting it running in the first instance is what's required. Edelbrocks are often lauded as running 'straight out of the box', but don't take that too literally! Some basic adjustment required.

    Chris
     
    Sharpone, 57Fury440 and Oneball like this.
  4. Oneball
    Joined: Jul 30, 2023
    Posts: 1,616

    Oneball
    Member

    PS if you’ve not even touched the throttle it’s probable the choke is open as it’s jammed on the fast idle cam. Blip the throttle see if it closes.
     
    Sharpone and 57Fury440 like this.
  5. Eth727
    Joined: Jun 20, 2024
    Posts: 327

    Eth727

    I haven’t touch anything. I need to mention that I have a vacuum gauge. I hooked up the vacuum line to the right but the gauge didn’t show anything. I moved it to the left and it works but on the left instead of the right.
     
  6. 19Eddy30
    Joined: Mar 27, 2011
    Posts: 3,832

    19Eddy30
    Member
    from VA

    Adjustments to choke and throttle blades are going to be needed,
    You're gonna have to get the vehicle running ,
    Start with backing choke off Not working,
    " completely open"
    Ajust Idle and enrichment screws @ operating temp.
    Check For Vacum leaks. Can of brake clean.
    Want's that set ,
    Let cool then start setting the choke adjustment,, Covered in paper work .
     
  7. Budget36
    Joined: Nov 29, 2014
    Posts: 15,242

    Budget36
    Member

    Plug your vacuum ports for now.

    A screw in a piece of tubing will plug them.

    Edit: Is the adapter in place, I don’t notice it?
     
    Sharpone likes this.
  8. ClayMart
    Joined: Oct 26, 2007
    Posts: 7,787

    ClayMart
    Member

    Just keep in mind that any carb with a choke will have two idle speed adjustments. One is usually called the high-speed or fast idle spec. It comes into play when the choke is set and the engine needs a higher idle speed to keep from stalling and to get the engine warmed up quicker with a richer fuel mixture.

    After the engine is up to temperature is when you set hot idle, or sometimes referred to as the curb idle speed. This is when the engine is warmed up, the choke is fully open and the engine no longer needs the richer fuel mixture.

    Your vacuum gauge should be connected to a source of full manifold with the engine at the curb idle speed. The user manual for the carb should indicate which port supplies manifold vacuum and which connection is ported or off-idle vacuum. Typically the full manifold vacuum port will be lower on the carb, usually below the throttle plates. The ported vacuum connection tends to be higher up on the carb, above the throttle plates.
     
    Sharpone likes this.
  9. Lone Star Mopar
    Joined: Nov 2, 2005
    Posts: 4,205

    Lone Star Mopar
    Member

    As has been said thats your fast idle. On the 1406 I just did, set that screw in your pic until it sits about the middle of the cam its resting on now.
    Then you can fine tune from there.
    Edelbrock usually includes decent setup instruction paperwork with a new carb.
     
    Sharpone likes this.
  10. Eth727
    Joined: Jun 20, 2024
    Posts: 327

    Eth727

    Yeah the adapter is a done deal. The carb is remanufactured . It didn’t come with anything but the carb so instructions. I watched YouTube videos from Edelbrock and they said it should run out of the box. I lowered the fast idle and it only goes to 900. I drove it around and it won’t idle to 500.
     
  11. Eth727
    Joined: Jun 20, 2024
    Posts: 327

    Eth727

  12. Moriarity
    Joined: Apr 11, 2001
    Posts: 37,205

    Moriarity
    SUPER MODERATOR
    Staff Member

    this is the idle speed screw, screw.png
     
  13. Moriarity
    Joined: Apr 11, 2001
    Posts: 37,205

    Moriarity
    SUPER MODERATOR
    Staff Member

    sometime a high idle is from a vacuum leak
     
  14. Moriarity
    Joined: Apr 11, 2001
    Posts: 37,205

    Moriarity
    SUPER MODERATOR
    Staff Member

    Maybe the linkage to the gas pedal is holding it part way open? try un hooking that and see if it idles down
     
  15. swade41
    Joined: Apr 6, 2004
    Posts: 14,415

    swade41
    Member
    from Buffalo,NY

    Disconnect your throttle pedal linkage to rule that out as a cause. If that's good I'd figure out a way to wire the choke flap wide open to rule that out.
    Next step would be spraying it to check for vacuum leaks, then hook up your vacuum gauge and adjust your mixture screws to get highest gauge reading.
    Everyone else pointed out your idle speed screw so obviously that's the first thing to adjust.
     
  16. Make sure the throttle rod from the car itself isn't holding it open. Sometimes, you have to adjust that too when fitting a new carb to your car.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 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.