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  • Engine: Periodic "Stutter"

    An intermittent problem has developed with my '63 R2 Hawk. The car will periodically develop a "stutter", if you will, when just driving down the road. It's almost like there's an electrical short or electrical crossfire happening (which I'm inclined to think because the Tachometer will bounce around like it's getting a power fluctuation).

    1) I have changed the spark plug wires/coil wire, but that isn't the issue.
    2) I thought it could be fuel-related, so the AFB carburetor has been rebuilt, but that's not the issue either.

    Oddly, when it happens,sometimes the cure is to turn the key off and then restart the car which works about 1 in every 3 tries. When it is happening, you can hear the misfire out the tailpipes, and the there is definitely a power loss. Also, when I come to a stop, the idle drops 200-300 RPMs. This is a 4 speed car, so when I accelerate from idle, the RPM picks right back up to driving power, but the problem resurfaces the moment you reach a cruising speed. This one definitely has me baffled, and I'm hesitant to drive long distances. Thoughts?

  • #2
    Points and condenser could be the problem. Those dual point distributors can be a trial. I would first just poor a couple bottles of Heat or Dry Gas in the tank. If you have put ethanol in it you have a big problem. The alcohol takes decades of crud off the linings of tank, gas lines, and float bowls and puts it into the passages and metering valve of the carb. That could be the problem 'cause the accelerator pump throws gas into the engine on acceleration but gas has to come thru clogged jets when cruising. I would check with Dave T. Jon Meyers, or Phil Harris about the rebuild; you probably don't want gas blowing all over that nice motor. Sounds like a super neat car; Super Hawk package car??

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    • #3
      Yes, it is a Super Hawk car. Stiff suspension, sway bars, disc brakes, and definately corners like a near modern automobile- way ahead of it's time for sure, especially given the 15" wheels and standard profile tires. In response to your suggestions, the dual point distributor was replaced with an electronic ignition distributor a few years back. There is certainly the possibility that something inside is failing, but there is nothing outwardly that I can see that is demonstrating such a failure (such as arcing). As it relates to the fuel, I run straight gas as I know the horrors ethanol-based fuel causes. Plus, the tank and fuel lines are all within a couple of years of age, plus the factory AC bowl-type filter is changed every 2,000 miles due to fuel quality/integrity. I'm inclined to think it's electrical, rather than fuel.

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      • #4
        I would definitely put the 2 cans of Heat in the tank. You live in Oregon where it can get almost as humid as Minnesota so condensation can occur. And it is cheap and easy and you should do it periodically anyway. If that doesn't work, is there a conventional distributor you could drop in it to see if that's the issue? I don't see fuel delivery as a problem , but AFB's can be fussy. Must be just awful to have such a nice car and be afraid to leave home in it. I've had electronic ign systems fail but on both cases the car just quit. (both due to faulty Chinese wires)

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        • #5
          Thanks, I'll start with the 2 bottles of Heat and go from there. I'll search out an original distributor as well.

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          • #6
            If this car has a pink 'resistance' wire to coil + it is always suspect. If it has the green/black wire and ceramic resistor to coil + the resistor could be going bad. Monitor voltage at coil + for awhile and see what it's doing.
            D 'N Q RACE ENGINES

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            • #7
              Your engine is cross firing.
              This happened a lot more with electronic ignition.
              This is not due to bad insulation on the plug wires but is induction from one wire to the next.
              Bundle #1 and #5 ignition wire together and #3 and 7 .
              The firing order for the Studebaker V8 is 1,8,4,3,6,5,7,2.
              You can see that $5 fires when #7 is in its compression stroke on the way up. Voltage induced by #5 ignition wire will fire #7 also if they are bundled together.
              When you separate #5 and #7 by bundling them as above this will not happen.
              A friend had a 1962 Hawk and was complaining that the engine would stumble and quit when he was at a stoplight.
              I rerouted his wires by bundling them as described above and it never happened again.
              On the 289 it was not uncommon that #7 piston had a hole blown out by this cross firing because the dished pistons had a much thinner top wall.
              This is induction that causes the problems and even if you have the best ignition wire set it will happen. Induction is what makes a transformer work.

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              • #8
                I think you have some rubbish in your intermediate carb. jet. With the carb. off and upside down, the butter fly shut, see the small round hole next to the butter fly, now open them up and just above them is the intermediate jet outlet. this is usual a slot not round. things can and do get lodged in the opening or be floating around in the passage behind it. Its gotta come out.

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                • #9
                  Whatever you do, do NOT fix more than ONE thing at a time until thoroughly testing it, or we will all go to our grave wondering WHAT fixed it!
                  StudeRich
                  Second Generation Stude Driver,
                  Proud '54 Starliner Owner
                  SDC Member Since 1967

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                  • #10
                    Originally posted by rkapteyn View Post
                    Your engine is cross firing.
                    This happened a lot more with electronic ignition.
                    This is not due to bad insulation on the plug wires but is induction from one wire to the next.
                    Bundle #1 and #5 ignition wire together and #3 and 7 .
                    The firing order for the Studebaker V8 is 1,8,4,3,6,5,7,2.
                    You can see that $5 fires when #7 is in its compression stroke on the way up. Voltage induced by #5 ignition wire will fire #7 also if they are bundled together.
                    When you separate #5 and #7 by bundling them as above this will not happen.
                    A friend had a 1962 Hawk and was complaining that the engine would stumble and quit when he was at a stoplight.
                    I rerouted his wires by bundling them as described above and it never happened again.
                    On the 289 it was not uncommon that #7 piston had a hole blown out by this cross firing because the dished pistons had a much thinner top wall.
                    This is induction that causes the problems and even if you have the best ignition wire set it will happen. Induction is what makes a transformer work.
                    Thank you greatly, I will try this simple fix and see what happens- appreciated!

                    Comment


                    • #11
                      Originally posted by StudeRich View Post
                      Whatever you do, do NOT fix more than ONE thing at a time until thoroughly testing it, or we will all go to our grave wondering WHAT fixed it!
                      LOL, no worries, will do!

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                      • #12
                        Another thing to check is the tach sender. The original tach senders have a reputation for failing shorted. You might try finding the wire from the distributor to the sending unit, and temporarily disconnecting it.

                        A fuel-related miss would not likely cause the tach needle to jump, if the coil is still sending spark to the distributor.
                        Gord Richmond, within Weasel range of the Alberta Badlands

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                        • #13
                          This "stutter"-does it occur in dry weather or just rainy or wet roads? I had an older car that would begin to self-short with an upward splash of street water.

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                          • #14
                            This car cannot be fixed...the insurance company would total it...better sell it to me...JK.
                            ^ All the above is great advice. Now that you've tried Heet, I'd follow bundling advice in post #7...worked for me!
                            Andy
                            62 GT

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                            • #15
                              I had a similar problem that eventually figured it out for me. That little stupid wire from the "Pass thru" in the distributor to the points had rubbed a hole in the insulation and would arc. eventually it shut down on me in Murfreesboro traffic. Cost me some pushing and a tow truck.

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