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    Carb tuning questions....

    Alright, I finaly did a quick rebuid on my holley this past weekend. It was stalling all over the place at stoplights and was flooding bad. So now that its rebuilt its been running reliably, but its still really far from where it should be. I changed out my seconday spring to the brown one too. It has a Bad bogg from flooring it at a stop, it will backfire once in a while doing that to. It also has a gurgling sound when I do that. Could my timing be to retarded? And it seems like it is very sluggish, could changing out my jets help? If so what jets should I try? It also backfires trying to start it cold, I keep setting my mixture but it never helps. Any ideas?

    2009 Ford F-350 6.4 powerstroke diesel. 1977 Ford F-150 built 300 six, 5 speed trans. 1976 MG MGB roadster, 359w, t5 5 speed. 1996 Kawasaki ninja ZX6R.
    My rod is glowing, my bead is clean, my middle name is acetylene

    #2
    Carbs . . . that takes me back . . . .

    Does the bog happen when you floor it? If so, is your accelerator pump working right? I don't know about your exact carb, but you can adjust the amount of the squirt as well as the duration on some carbs. You should be able to see the gas been squirted in if you look down into the carb and operate the throttle by hand.

    If the bog happens a second or so after you floor it, I'd look at the jetting.

    The secondary spring won't come into play until the revs come up (and the vacuum through the venturies come up as a result). The differing springs, from what I remember, controls when (or how soon as the revs/load rises) the secondaries open.

    Then there is always proper float setting - too high and too low can cause problems.


    HO with Explorer Cam, Electric Fan, Cop Sway Bars, Dual exhaust with no mufflers, 15x7" American Racing; 215/70R15's front, 255/60R15's rear, 3.55's with Trak-Lok.

    Comment


      #3
      float setting is as close to good as I can get it, and yes the bog and gurgling sound happens as soon as I floor it. It usually doesnt like to be floored until its above 2500 rpm guessing.

      2009 Ford F-350 6.4 powerstroke diesel. 1977 Ford F-150 built 300 six, 5 speed trans. 1976 MG MGB roadster, 359w, t5 5 speed. 1996 Kawasaki ninja ZX6R.
      My rod is glowing, my bead is clean, my middle name is acetylene

      Comment


        #4
        Timing, mang.

        You SURe you have it set at 10 degrees ATDC? You might have it set BELOW...
        1983 Grand Marquis 2Dr Sedan "Mercules"
        Tremec TKO conversion, hydraulic clutch, HURST equipped!

        Comment


          #5
          check and set the timing and that might help a little bit

          RIP Jason P Harril, we'll miss ya bro

          '80 Town Coupé
          '84 Towncar - Teh Cobra TC, 408w powered
          '16 Ram 1500 CC Outdoorsman, Hemi/3.92/8sp 4x4

          Comment


            #6
            From the Holley web-site:

            QUESTION My vehicle has a stumble from a dead stop. What can I do to cure this?

            ANSWER The most common cause of a stumble is not having an adequate accelerator pump shot. The first thing to do is to look at the discharge nozzle and make sure you are getting a good strong pump shot. If not then you need to inspect the pump diaphram for a hole or tear. You will also need to make sure that the pump passage is clear from any trash or debris. First you will need to check the adjustment on the pump. To do this you will open the throttle all the way (WOT). Push the pump arm lever down and then adjust the pump override spring to obtain .015" clearance between the pump arm and lever. If you are having a stumble and no black smoke out the tailpipe then you will need to increase the shooter size. If it stumbles and you are getting black smoke from the tailpipe then it will be nessasary to decrease the shooter size.

            Go here for more:



            HO with Explorer Cam, Electric Fan, Cop Sway Bars, Dual exhaust with no mufflers, 15x7" American Racing; 215/70R15's front, 255/60R15's rear, 3.55's with Trak-Lok.

            Comment


              #7
              Too much fuel enrichment from the accelerator pump.
              Builder/Owner of Badass Panther Wagons

              Busy maintaining a fleet of Fords

              Comment


                #8
                Another good site:



                HO with Explorer Cam, Electric Fan, Cop Sway Bars, Dual exhaust with no mufflers, 15x7" American Racing; 215/70R15's front, 255/60R15's rear, 3.55's with Trak-Lok.

                Comment


                  #9
                  Originally posted by Grand_Marquis_GT
                  Timing, mang.

                  You SURe you have it set at 10 degrees ATDC? You might have it set BELOW...

                  Has to be BEFORE top dead center, not after.
                  86 Lincoln Town Car (Galactica).
                  5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                  91 Lincoln Mark VII LSC grandpa spec white and cranberry

                  1984 Lincoln Continental TurboDiesel - rolls coal

                  Originally posted by phayzer5
                  I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                  Comment


                    #10
                    Originally posted by 89GrandMarquis
                    From the Holley web-site:

                    QUESTION My vehicle has a stumble from a dead stop. What can I do to cure this?

                    ANSWER The most common cause of a stumble is not having an adequate accelerator pump shot.
                    That only applies to a performance motor that actually needs more fuel and it assumes that your timing is correct. Neither of which are probably true.

                    Comment


                      #11
                      I should set the timing at what, 12*? Or should I try something different?

                      2009 Ford F-350 6.4 powerstroke diesel. 1977 Ford F-150 built 300 six, 5 speed trans. 1976 MG MGB roadster, 359w, t5 5 speed. 1996 Kawasaki ninja ZX6R.
                      My rod is glowing, my bead is clean, my middle name is acetylene

                      Comment


                        #12
                        What kind of timing advance are you using? Does the Dist have vacuum advance?
                        Builder/Owner of Badass Panther Wagons

                        Busy maintaining a fleet of Fords

                        Comment


                          #13
                          yeah, it has a vac advance on it

                          2009 Ford F-350 6.4 powerstroke diesel. 1977 Ford F-150 built 300 six, 5 speed trans. 1976 MG MGB roadster, 359w, t5 5 speed. 1996 Kawasaki ninja ZX6R.
                          My rod is glowing, my bead is clean, my middle name is acetylene

                          Comment


                            #14
                            Have you made sure it all works?
                            Builder/Owner of Badass Panther Wagons

                            Busy maintaining a fleet of Fords

                            Comment


                              #15
                              Originally posted by Mercracer
                              That only applies to a performance motor that actually needs more fuel and it assumes that your timing is correct. Neither of which are probably true.
                              Uh - no.

                              If "regular" or "stock" cars didn't need an accelerator pump, then they wouldn't have one from the factory, which they do.

                              Heck, my 1970 VW Bug would cough if the accelerator pump wasn't working right.

                              When you bolt on an aftermarket carb, the accelerator pump shot must match the engine. Sometimes, it is close enough out of the box, but sometimes, not.


                              HO with Explorer Cam, Electric Fan, Cop Sway Bars, Dual exhaust with no mufflers, 15x7" American Racing; 215/70R15's front, 255/60R15's rear, 3.55's with Trak-Lok.

                              Comment

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