Holley surges while cruising

Discussion in 'Troubleshooting & Diagnosis' started by atakrator, Oct 13, 2009.

  1. atakrator

    atakrator Member

    76
    0
    Apr 29, 2005
    Waterford, MI USA
    During normal driving or decelerating, my engine seems to surge forward. While accelerating, I don't have this problem at all.
    All I can think of is gas - perhaps the secondaries - is dripping down the carb, and is unnoticed while speeding up cuase it's being used up anyway.
    Has anyone ever heard of this? Maybe my floats are too high, but I am pretty sure I checked them.
    For referance, I am running a holley 650 in a chevy350. I took the holley apart a few weeks ago to see what jets it had, and to see how it worked (I have mainly had edelbrocks and am possibly switching over to the holleys)
    thanks
     
  2. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

    8,698
    1
    Sep 20, 2004
    Southern Maryland
    Have you rebuilt this carb? If not and it's not a new carb, do so as a starting point. If the float needle valves are old, it's gonna be sketchy adjusting float level and tuning. Also if it's an old carb it probably doesn't have power valve blowout protection. Surging during cruise usually means lean though.
     
  3. atakrator

    atakrator Member

    76
    0
    Apr 29, 2005
    Waterford, MI USA
    No - I have not rebuilt the carb, and yes - it is older. I got it in a swap meet. Ran kinda OK but never really ran great. Infact, the only time it did run good was during acceleration.
    I have idle problems also. As soon as I put it in gear, it stalls out. So I leave it in nuetral while stopped, and rev it up a bit as I put it into gear.
    But I figured I would tackle on issue at a time!
     
  4. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

    8,698
    1
    Sep 20, 2004
    Southern Maryland
    A non rebuilt holley is never gonna run right. Anything soft in that carb, is going to be dried out. Tric kit it before you waste too much time on it.
     
  5. hhott71

    hhott71 Veteran Member Lifetime Gold Member

    14,375
    1
    Mar 30, 2001
    Joplin Mo. 64801
    Add a 1/8-1/4 turn to the idle mixture screws, noting your starting position so you can return it to that point if needed.
    Take it for a drive.

    #2, Spray Gumout don the small bleed holes in the top of the barrels.
    You can also rev the motor to 2000-2500 or so and holding a rag in your hand, smother the carb opening. All that vacuum will suck out any micro dirt in the metering block.

    Price to try? Nothing but the spray can of Gumout.
     
  6. Bikefixr

    Bikefixr Veteran Member Lifetime Gold Member

    1,643
    20
    Mar 13, 2006
    Hott71 gave good advice. Holleys are VERY sensitive to dirt. Clean it up and clean it out. You're not surging when you accellerate because the power-valve is open under laod and richening up the mixture. Back out your idle screws 1/4 turn, that will stabilize the idle and help slow-speed metering. Holley carbs run on the idle circuit up to about 2000 RPM at light throttle. Your cruise surge can be because your jetting is borderline too lean. The switch to winter formulation gas can make a borderline mix go a bit lean. Add 2 jet sizes in the primaries in the winter and it should do just fine. Holleys do not dribble out of the secondaries.
     
  7. atakrator

    atakrator Member

    76
    0
    Apr 29, 2005
    Waterford, MI USA
    OK - I will start by resetting my idle screws - chances are I will end up rebuilding. It did sit for about a year. I will also pick up a jet kit.
    Thanks for the advice!
     
  8. Camaro11

    Camaro11 Veteran Member

    2,669
    0
    Jul 10, 2003
    Atlanta, GA, USA
    As a LONG time Holley owner, I both second and third this motion.

    Get the Gummout can nozzle-tube right on the Idle Air Bleed orifices and
    go to town. They clog up all the time.

    I don't know about re-jetting for the Winter (I live in GA).

    What is the model # on your Carb ?
     
  9. jtaddeo1

    jtaddeo1 New Member

    7
    0
    Oct 3, 2009
    Chicago, il
    I have the same problem with a Holley 1850 650cfm carb and bought the rebuild kit. Going to do it and see what happens. My history with Holleys tells me that the above replies are correct. The Holleys clog up easily. If the car hadn't come with a Holley on it I would have bought an Edelbrock carb. Never had the problem with them as long as the gas was good quality and you use a good filter.
     
  10. atakrator

    atakrator Member

    76
    0
    Apr 29, 2005
    Waterford, MI USA
    Maybe a dumbass question, where exactly do I spray the gumout?
    Where are the "air belld orifices"
     

Share This Page