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1950 Champion acceleration problem

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  • 1950 Champion acceleration problem

    I am getting down to a relatively short fix-it list on my 1950 Champion. One of the problems that I haven't yet fixed is a tendency for the car to stall when I commence acceleration. It also has a sort of "flat spot" in acceleration, about one-third of the way through each of the gears. I didn't notice this problem right away when I got the car runing, but it might have been masked by other problems, like my bad old fuel pump.
    I have new plugs, wires, cap, rotor coil, condenser. I have rebuilt the carb and replaced the fuel pump, even put in a new, longer (20" long) fuel line from fuel pump to carb to reduce vapor lock (it seems to help). Dwell and point gap are all set pretty right. Timing seems to be in the right range (pings a little at high revs under load) although my timing light went bad, so I can't be sure that isn't part of the problem. I use regular unleaded gas.
    A mechanic friend told me to check my vacuum advance by disconnecting it at the manifold, hooking up a hose and sucking on it. If the hose wouldn't draw, the advance would be ok. Otherwise, there is a leak. First time I did that, a small amount of gas came out! (Where did that come from?) I did it again later and just got fumes, and it seemed like it drew pretty hard, but didn't stop drawing completely. Vac. pipe fittings seem to be ok and are tight. Vac. wipers work ok.
    Having said all this, I came to the conclusion that the likely culprit of the hesitation is the vacuum advance, aka spark modifier. Trouble is that I can't find a replacement. Not at Stude Intl., not in Cathcarts or Fairborn's on-line catalogs, not on eBay, nowhere.
    1. Does anybody have a NORS vacuum advance for an Autolite IAT 4001 distributor (used in late 1950 to 54 Champions, maybe some trucks), or can you point me to a vendor or even know a current part #?
    2. Is there a better test of vacuum advance than sucking on the pipe?
    3. Any other ideas for the cause of the hesitation and "flat spot" in acceleration?
    4. Why is gas in my vac. pipe?

    I would appreciate anybody's help with any of the above issues.

    Thanks,



    1950 Champion 4 Dr.
    Holdrege NE
    John
    1950 Champion
    W-3 4 Dr. Sedan
    Holdrege NE

  • #2
    I have checked a number of vacuum advances by sucking on the pipe, but a small hand vacuum pump would be better. The ones I have seen have a guage and you can hold the vacuum and see if it leaks down. Someone else may suggest a brand.


    1952 Champion Starlight, 1962 Daytona.Searcy,Arkansas
    "I may be lazy, but I'm not shiftless."
    "In the heart of Arkansas."
    Searcy, Arkansas
    1952 Commander 2 door. Really fine 259.
    1952 2R pickup

    Comment


    • #3
      "Mighty-Vac" Available in kit form for use as you need, as well as bleeding brakes, and many other uses. Most major parts store sell them, or something similar. Hope this helps.

      Dan Miller
      Atlanta, GA

      [img=left]http://static.flickr.com/57/228744729_7aff5f0118_m.jpg[/img=left]
      Road Racers turn left AND right.

      Comment


      • #4
        Thanks for the tip on using a vacuum pump to test my vac. advance. Assuming it is bad, where do I get a replacement? And how did gas get into the vac. pipe? Any ideas?

        1950 Champion 4 Dr.
        Holdrege NE
        John
        1950 Champion
        W-3 4 Dr. Sedan
        Holdrege NE

        Comment


        • #5
          Although I have a v8 I had the same trouble with the stall under acceleration. Had a new fuel pump and carb had just been rebuilt. It came down to a bad pump. I took the output line to the carb off and when cranked gas just dribbled out. Should spurt. New doesn't mean good.

          John Ratliff

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          • #6
            I found a couple of possible part numbers in an old NAPA book. Their house brand of electrical parts is Echlin. Echlin VC190 and VC175 fit IAT 4001 and 4011 distributors used in Dodge vehicles. There is no listing earlier than '58 for Studebaker vacuum control units. This doesn't mean that the others won't work - it just means that when this catalog was condensed in the late 70s, they probably overlooked all the possible applications. Especially as related to the then already obsolete Studebaker.

            One thought of mine on this flat spot. I know you said the carb's "rebuilt", but simply knowing it has had a kit installed in it doesn't automatically mean it's like new again.
            Crank it over a bit to insure the carb's full of gas. Then go out and look down the throat of the carb. Holding the choke open, work the throttle. There's GOT to be a steady stream of fuel squirted into the throat from the moment you start to move the throttle. IF you can move the throttle open AT ALL before a squirt starts, you're gonna have an annoying flat spot when you take off.
            What happens with the old carbs is that the linkage gets sloppy with age and affords some throttle plate movement before the accelerator pump gets actuated enough to "play along". That lack of squirt initially will cause a stumble.

            Miscreant Studebaker nut in California's central valley.

            1957 Transtar 1/2ton
            1960 Larkvertible V8
            1958 Provincial wagon
            1953 Commander coupe
            1957 President two door

            No deceptive flags to prove I'm patriotic - no biblical BS to impress - just ME and Studebakers - as it should be.

            Comment


            • #7
              Mr. Biggs
              First of all, thanks for the part #s. Both of those Echlin Vac. advances are available at my FLAPS. I ordered VC-190 first, but it isn't quite right. The mounting is the same, but, instead of a straight lnking arm to the distributor, it has an angled one, and I don't see how to adapt it. It also has a male hose fitting, instead of a female vac. pipe fitting, although I could adapt that. I will order VC-175 and see if it will work.
              You were right on about the carb! There is a definite lag before the accelerator pump starts squirting. How do I fix that?
              By the way, there was also a suggestion that the fuel pump might be bad. I tested it and it is pumping OK.

              1950 Champion 4 Dr.
              Holdrege NE
              John
              1950 Champion
              W-3 4 Dr. Sedan
              Holdrege NE

              Comment


              • #8
                Lothar,

                Since I can't see your carb, I'm not sure what the linkage looks like. But on the Stromberg WW 2bbls that Stude used on V8s for the last 11 years of Stude V8s, there's a link rod between an arm on the throttle shaft and the lever than mounts to the top cover of the carb. Over the years, slop develops in this arrangement and I found a rather fine, wire retraction spring that I could attach to the lever and the throttle shaft arm. It doesn't take the place of the rod, but it effrectively takes the slop out of it's connections and thereby eliminates the lag in accel pump actuation!
                You might also look and see if there's alternate holes for any linkages to use that might afford more action when the throttle's worked.

                Miscreant Studebaker nut in California's central valley.

                1957 Transtar 1/2ton
                1960 Larkvertible V8
                1958 Provincial wagon
                1953 Commander coupe
                1957 President two door

                No deceptive flags to prove I'm patriotic - no biblical BS to impress - just ME and Studebakers - as it should be.

                Comment


                • #9
                  Mr. Biggs
                  Thanks for the ideas, I'll see what I can rig up.

                  1950 Champion 4 Dr.
                  Holdrege NE
                  John
                  1950 Champion
                  W-3 4 Dr. Sedan
                  Holdrege NE

                  Comment

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