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Auto Choke adjustment in 64 Hawk

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  • Fuel System: Auto Choke adjustment in 64 Hawk

    All,

    My 64 hawk takes a while to start and I think the root of the issue is the auto-choke. Is there an adjustment that can increase the choke when it is engaged?

    Sorry, I know very little about this system and am trying to learn.

    Thanks!
    dsd
    1964 Studebaker GT Hawk
    1970 Jaguar E-Type 2+2
    2003 Ferrari 575 Maranello (3 Pedal)
    2007 Jaguar XK Convertible
    2011 Jaguar XJL 5.0 SC

  • #2
    Either the choke is fully engaged or it isn't. Of course you can adjust it so that it stays closed longer, but this will not help with starting, it will only give too rich running.

    If your choke is fully closed before a cold start, that is not your problem. You probably have evaporation of modern fuel. Check that you choke fully closes when the engine is cold and the throttle is depressed slightly to release the choke plate.
    Gary L.
    Wappinger, NY

    SDC member since 1968
    Studebaker enthusiast much longer

    Comment


    • #3
      Can someone confirm the procedure:

      Prior to start, I depress the accelerator all the way down and slowly release. That should engage the auto choke.

      I then start the car and do not provide extra gas.

      On my car after 3 or 4 long cranks the car catches and starts.

      Thanks.
      1964 Studebaker GT Hawk
      1970 Jaguar E-Type 2+2
      2003 Ferrari 575 Maranello (3 Pedal)
      2007 Jaguar XK Convertible
      2011 Jaguar XJL 5.0 SC

      Comment


      • #4
        See your shop manual and set the choke unloader setting (gap between choke butterfly and carb body) It is usually 3/16" --check the manual-- measured with throttle open and carb cold. Use drill bit, but don't drop it! From there, make small adjustments rich or lean. The choke steps down as the engine warms up. It is not 'on or off'

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        • #5
          Prolonged cranking before the car starts is the new normal for our old cars, when fueled up with today's ethanol-adulterated fuel. If the car sits for a few days between uses, the fuel will simply evaporate out of the carburetor bowl, leaving the level low enough that cranking vacuum cannot draw what's left through the jets. The choke helps little in this case. I removed the mechanical fuel pump, and mounted an electric back by the tank. Let the pump run a few seconds before cranking the engine, and it will light right off as soon as you crank it. Today's fuel is much different than what was sold in the 1960's, and it is unreasonable to expect that our cars will function perfectly on it without some modifications being made. Pretty well all modern cars have EFI, with closed, pressurized fuel systems that are inherently immune to percolation, vapor lock, and evaporation of the gasoline.

          I do have an '88 Chevy pickup with EFI, and it has a leaky check valve on the fuel rail. It won't start on the first crank after a day's idleness. But crank 2 seconds, wait 5, and crank again, and it starts fine; fuel pump just has to catch up. I could fix it, but it's not at the point of being a problem, yet.
          Gord Richmond, within Weasel range of the Alberta Badlands

          Comment


          • #6
            gordr Thanks, I had not thought of an electric fuel pump. Would this also help with vapor lock?
            1964 Studebaker GT Hawk
            1970 Jaguar E-Type 2+2
            2003 Ferrari 575 Maranello (3 Pedal)
            2007 Jaguar XK Convertible
            2011 Jaguar XJL 5.0 SC

            Comment


            • #7
              Originally posted by dsd View Post
              gordr Thanks, I had not thought of an electric fuel pump. Would this also help with vapor lock?
              Absolutely. Vapor lock happens when the fuel in the suction line to the fuel pump gets hot enough to boil. The pumps winds up sucking vapor, and not liquid, and the carb runs out of gasoline. A related problem is percolation, where gasoline in the carb bowl boils, and vapor pressure floods the manifold with liquid gasoline, and, then that boils, too. With an electric fuel pump at the rear, the line going forward is now under pressure, and the boiling point is raised. Even if a bubble of vapor does form, pressure from the pump will force it through the line to the carb, where it can escape via the bowl vent.

              If you have the electric pump on a toggle switch, one trick you can do is to shut off the fuel pump a few moments before parking the car. Finish your parking maneuvers on the fuel remaining in the carb bowl, and once parked, let it idle until the carb runs dry and it quits. No fuel in bowl means no percolation to flood the carb on a hot restart, say after refueling. Just kick on the pump, let it run a few seconds, and fire up.

              By rights, and electric fuel pump installation needs to have safety circuitry so that the pump will stop running if the engine stops. That helps prevent fires in the event of a front-end wreck or roll-over. All modern cars with EFI have that built in. For us, an oil pressure switch to control the pump through a relay is the normal choice, but there are electronic relays that get an "engine running" signal from tach pulses from the distributor. too. I would add the toggle switch to positively turn the pump off (also works as a theft deterrent), and a push button to run the pump momentarily with the engine off, so you can fill a dry carb before cranking the engine.
              Gord Richmond, within Weasel range of the Alberta Badlands

              Comment


              • #8
                gordr Great info, thanks. Is there a kit to do this right? Any suggested pump for a 64 R1 Hawk?
                1964 Studebaker GT Hawk
                1970 Jaguar E-Type 2+2
                2003 Ferrari 575 Maranello (3 Pedal)
                2007 Jaguar XK Convertible
                2011 Jaguar XJL 5.0 SC

                Comment

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