Carb'd Chevy 350 Question - Carb backfire

Discussion in 'GM/Chevrolet' started by FJ40_owner, Mar 17, 2008.

  1. FJ40_owner

    FJ40_owner

    Joined:
    Aug 16, 2005
    Messages:
    818
    Location:
    El Dorado County CA
    My 40 has a 78 350 installed. I run a Rochester 2 barrel carb. There is no smog stuff on it. Recently when running at moderate rpm, say 2000, engine is warm, when I put my foot into it the engine will sneeze through the carb.

    My stock 40 used to do this and the solution was a new gasket around the accelerator pump, as I recall.

    The only PM I have done is fluid changes, air filter and plugs. The PM was done months ago.

    I run regular CA fuel.

    Should I check the timing or might something be wrong with the carb?
    The choke is OK and not stuck closed.

    Thanks,

    BigJim
     
  2. Gumby

    Gumby Supamod Staff Member s-Moderator

    Joined:
    Dec 13, 2002
    Messages:
    11,155
    Location:
    Knee deep in hookers and gin
    Accelerator pump sounds like the culprit.
     
  3. baxter650

    baxter650

    Joined:
    Aug 8, 2005
    Messages:
    1,565
    Location:
    Grand Forks B.C.
    Engine off, look down the carb throat, move throttle to w/o, look for pump shot.
     
  4. Gumby

    Gumby Supamod Staff Member s-Moderator

    Joined:
    Dec 13, 2002
    Messages:
    11,155
    Location:
    Knee deep in hookers and gin
    definitely with the engine off. You'll look goofy without eyebrows.
     
  5. NeverSummer

    NeverSummer

    Joined:
    Mar 8, 2007
    Messages:
    36
    Location:
    Santa Rosa, Ca
    LMAO! I have seen this happen!
     
  6. Chevinater77

    Chevinater77

    Joined:
    Feb 10, 2007
    Messages:
    235
    Location:
    Wenatchee, Washington
    my 72 chevy 2 wheel drive long bed with a 350 with a 2 barrel carb does this with bad gas. We just picked the rig up so i plan to get a carb "rebuild" kit. and do the gaskets and new filters for it! Mine only did it around 50-60 MPH. and only when in drive. when i ran premium it stopped doing it so much but still did a little!
     

Share This Page