Bog down at stopping...

Discussion in 'The Venerable Q-Jet' started by Electra-fied, Jun 3, 2021.

  1. Electra-fied

    Electra-fied GR8WHTE

    I rebuilt my Rochester and it runs great until you come to a stop. Just before the car comes to a stop, the engine starts to bog down to just above a stutter and then it recovers and idles perfect. No issue at acceleration or cruise. It doesn't die out completely, just sounds like it's either starving for fuel or getting to much fuel... Most likely from the force of car stopping. Thoughts?
     
  2. john.schaefer77

    john.schaefer77 Well-Known Member

    Float too high?
     
  3. Cliff R

    Cliff R Well-Known Member

    Not enough info.

    What is the carburetor part number?

    What type of float was installed?

    What float height?

    Diameter of the fuel inlet seat (the hole the needle seals).

    What fuel pump and fuel pressure?......
     
  4. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

    Check the one-way valve in the brake booster.
    Replace it if you can suck and blow air through it from the same side.

    Brake v.jpg
     
    Max Damage likes this.
  5. Electra-fied

    Electra-fied GR8WHTE

    Well...i was hoping for something simple too. The brake booster one way valve is good. The other questions i do not have the answers too. I left the float alone other than removing it up a tad to remove the needle. Everything is stock and I didnt do anything more than replace accel pump, the two body gaskets, needle and seat. Car runs great and idles fine...once it comes to a stop. It just that one moment as you are coming to a stop when its a little boggy and then it returns to nice smooth idle. I did have to perform an "oh ****" stop yesterday...my passengers in the back were in the front seat by the time we came to a stop...car was still running.
     
  6. Cliff R

    Cliff R Well-Known Member

    You didn't answer any of the questions above.

    Carburetor part number?

    What type of float is it using?

    What diameter is the hole in the fuel inlet seat?

    What is the float height set at?

    Type of pump and fuel pressure?

    Also, is the timing ROCK SOLID at idle speed each time you rev up the engine and let it return to idle?

    Something as simple as the mechanical advance sticking or weak springs will cause inconsistent idle speed and quality.......
     
  7. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    I'd put a cold beer on it the issue is the float height, especially since you replaced the needle and seat and didn't set the height. It's probably too high.
     

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