Holley DP issue with low RPM decelerating..

Discussion in 'Holley' started by VinMan, Mar 5, 2013.

  1. VinMan

    VinMan Well-Known Member

    Hey Buick friends,
    If you search by my user name you can get ALL the history on my GSX. To summarize, the engine build and set up in my auto-sig has been better than I could have ever imagined. Once I installed this engine and tuned it 5-ish years ago I have literally not had to touch the carb, timing or anything since. Besides regular oil changes it just runs & runs....I also drive it on a regular basis and living in CA helps

    Here's my question, recently if I have a hard stop for a light while in drive, lower RPM, the carb loads up and wants to stall, so I have to put in N and rev it to get through the issue. If I'm driving it aggressive and manually down shifting the T400 keeping the RPM's up when stopping, no issue.

    Any advice on this issue & how to solve it is appreciated..... I'm 25+ years removed from working on my last Holley, spent most of those years working on Q-Jets.

    Let me know if you think this is a float-sticking issue or something else.

    Also, Its time for me to clean the fuel filter between the pump and carb, so that will be done this next weekend

    Thx
    VinMan
     
  2. Golden Oldie 65

    Golden Oldie 65 Well-Known Member

    Replace the needle and seat assemblies. On a Holley you don't even have to remove the carb to do that and you should be able to buy what you need separately without having to buy an entire rebuild kit.
     
  3. 462 Chevelle

    462 Chevelle 462 chevelle

    I had a qjet that done this and I was told its from the throttle blades slamming shut and the engine vacuum pulling fuel from the carb and getting more air and that I needed a dash pot and also heard that's common with a Holley dp
     
  4. doc

    doc Well-Known Member

    Automatic cars neeeeed the dashpot on and working.... or it will do what you are describing....but a good electrical tune up and fuel filter change along with setting the idle screws and throttle stop screw would not hurt anything....:grin:
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Try lowering the rear float level. My AED 1000 carburetor does that. When I asked around about this, I was told that guys lower the rear float level on the street, and raise it back up at the track. Try it.
     
  6. VinMan

    VinMan Well-Known Member

    Thx for the feedback guys, been real busy with work traveling to Austin...Denver...Irvine and San Diego the last week, hense the late reply

    I will find the time to work on this SAT after my 8 yr old daughters cheerleading basketball game and my 6 yr old daughters softball game...


    VinMan out...
     
  7. mhgs

    mhgs it just takes money !!

    Vin :

    Mark from aptos..I used to live in mh and we met at the gym....I have the 70 gs...anyways, I would bet your idle mixtures are too lean and if you richen them up a bit you'll be good.
     

Share This Page