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My Model A stalls when I come to a complete stop. Help


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This has been bothersome as then I become stranded at stop lights and signs. My Model A keeps stalling when I come to a complete stop and complete stop only. My foot is pressed down on the clutch all the way when this happens. I shift into neutral when slowing down or coming to a stop. So my car stalls when coming to a complete stop when I have it in neutral. It stalls when I'm hitting the brakes hard. Can any of you knowledgeable folks help me pinpoint what could be the problem? Thank you I much appreciate it

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This is a common problem with Fords. Is your car idling okay,usually stalling can be traced to poor idle. Chances are that your miixture is too lean and when you stop quickly the fuel rushes forward and starves the secondary well and the engine essentially runs out of gas. Try enrichening the idle mixture and see if that helps. Also you may want to check to see if the fuel bowl level is correct also. Also make sure that you run your car with the fuel adjusting rod about 1/4 of the way opened after warmup.Also ,make sure that the engine idle speed is fast enough to power a hot engine as the engine idle will slow as the engine heats up due to friction. Hope this helps

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This is a common problem with Fords. Is your car idling okay,usually stalling can be traced to poor idle. Chances are that your miixture is too lean and when you stop quickly the fuel rushes forward and starves the secondary well and the engine essentially runs out of gas. Try enrichening the idle mixture and see if that helps. Also you may want to check to see if the fuel bowl level is correct also. Also make sure that you run your car with the fuel adjusting rod about 1/4 of the way opened after warmup.Also ,make sure that the engine idle speed is fast enough to power a hot engine as the engine idle will slow as the engine heats up due to friction. Hope this helps

Thank you for the reply. Im sorry I have very little knowlede regarding carburators. All Ive been tought in school is fuel injection. How to I go about enriching the idle mixture? How would I know if the fuel bowl level is correct and how to I adjust that? Is the fuel adjusting rod (choke?) that knob on the passenger side insode the cab?

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First I would recommend getting the book "The Model A Carburetor" by Paul Moller,available at any "A" parts house. The idle air adj. screw is the on in the front upper body just before the manifold connection. It turns clockwise to lean out and counterclockwise to enrichen. Start your engine and let it warm up. Turn the idle speed adj. screw( the upper screw on the throttle lever) out until the motor idles at it's slowest speed without stalling. Then turn the idle air screw clockwise until the engine wants to stall. The engine should stall if the screw is turned too far one way or the other;if it does not , you have other problems. Now turn the idle air screw counterclockwise until the engine wants to stall. Now turn it back clockwise until the engine will run evenly without rocking. Theoretically, all adjustments should be made after making sure the timing is correct. After adjusting the air turn the idle speed screw in just enough to make the engine run smooth. The gas adjustment and the choke rod is one and the same. Before you start a cold engine(and always start the engine with the spark lever fully retarded(all the way up),turn the choke rod knob clockwise until it just seats and the turn it counterclockwise one full turn. This enriches the mixture a little to aid startup. After it warms up close the rod and then open it about 1/4 of a turn for regular driving. To make a quicky check of the float position you must first remove the lower body of the carb. Actually it's easier if you just remove the carb. turn the upper carb upside down so that the float rests on the needle valve. Measure from the float's surface to the machined surface of the upper body. The float should be parallel to the body and the distance apart should be about 5/8 in. If the float is not parallel add or subtract gaskets under the fuel valve to remedy this. The Model A carb. is very simple but there are a lot of conditions that can affect it's performance,to many to list here. Good luck ! If you're having problems please feel free to call at 814-322-4481 EST. Jim

Edited by jpage (see edit history)
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First I would recommend getting the book "The Model A Carburetor" by Paul Moller,available at any "A" parts house. The idle air adj. screw is the on in the front upper body just before the manifold connection. It turns clockwise to lean out and counterclockwise to enrichen. Start your engine and let it warm up. Turn the idle speed adj. screw( the upper screw on the throttle lever) out until the motor idles at it's slowest speed without stalling. Then turn the idle air screw clockwise until the engine wants to stall. The engine should stall if the screw is turned too far one way or the other;if it does not , you have other problems. Now turn the idle air screw counterclockwise until the engine wants to stall. Now turn it back clockwise until the engine will run evenly without rocking. Theoretically, all adjustments should be made after making sure the timing is correct. After adjusting the air turn the idle speed screw in just enough to make the engine run smooth. The gas adjustment and the choke rod is one and the same. Before you start a cold engine(and always start the engine with the spark lever fully retarded(all the way up),turn the choke rod knob clockwise until it just seats and the turn it counterclockwise one full turn. This enriches the mixture a little to aid startup. After it warms up close the rod and then open it about 1/4 of a turn for regular driving. To make a quicky check of the float position you must first remove the lower body of the carb. Actually it's easier if you just remove the carb. turn the upper carb upside down so that the float rests on the needle valve. Measure from the float's surface to the machined surface of the upper body. The float should be parallel to the body and the distance apart should be about 5/8 in. If the float is not parallel add or subtract gaskets under the fuel valve to remedy this. The Model A carb. is very simple but there are a lot of conditions that can affect it's performance,to many to list here. Good luck ! If you're having problems please feel free to call at 814-322-4481 EST. Jim

Thank you for being so informative Jim. I plan on playing with the carb a little more once it gets a little warmer(I'm located in MA). I would imagine the float level is fine as the gasket that's in there has been since my grandfather restored the car in the 70's. He knew what he was doing so I don't think float level could be the problem. Regarding the choke rod knob, I was unaware that turned. I read inside one of my service books that the knob should be turned 1/4 turn off its seat. I just played with it a moment ago and I could turn it 2 full turns both clockwise and counterclockwise. I was afraid to go more as the book I have said not to crush it down on its seat as it could damage parts inside the carb. I could turn it with some resistance but I never could find its seat. Like I said I was afraid to turn it more. How many turns does it turn till it touches its seat?

I'm confident somethings not adjusted right on the carb. My friends and I took it apart 2 years ago to clean it out and we must have misadjusted something when we put it back on.

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Disconnect the rod from the needle at the carb by sliding the sleeve up the rod until you can remove it from the needle. See if you can turn the needle with your fingers until it seats. You can remove the needle buy turning it counterclockwise until it comes out. There is a removable brass seat inside the upper body that may be bad or missing. Remove the carb and look down the opening to see if the seat is in there. Also check to make sure that the needle itself is not broken. You should not have to turn the needle more than a full turn open, all that does is make the fuel mixture richer than it should be and could damage the engine. The gasket I was speaking of is not the bowl gasket but the one under the fuel inlet valve. I have found in some "rebuilt" carbs that there may be no gaskets or several gaskets in place,especially under the jet nozzles. All the adjustment needles are sharply pointed to seat in a fine hole. If you screw them in too tight all it does is damage the needle and they won't seat . I like to be of more help but it's hard to diagnose problems without looking at the car. You may check with MAFCA or MARC to see if there is a chapter near you. If you can find someone locally who really knows A's they can be a great help. Good Luck Jim

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Disconnect the rod from the needle at the carb by sliding the sleeve up the rod until you can remove it from the needle. See if you can turn the needle with your fingers until it seats. You can remove the needle buy turning it counterclockwise until it comes out. There is a removable brass seat inside the upper body that may be bad or missing. Remove the carb and look down the opening to see if the seat is in there. Also check to make sure that the needle itself is not broken. You should not have to turn the needle more than a full turn open, all that does is make the fuel mixture richer than it should be and could damage the engine. The gasket I was speaking of is not the bowl gasket but the one under the fuel inlet valve. I have found in some "rebuilt" carbs that there may be no gaskets or several gaskets in place,especially under the jet nozzles. All the adjustment needles are sharply pointed to seat in a fine hole. If you screw them in too tight all it does is damage the needle and they won't seat . I like to be of more help but it's hard to diagnose problems without looking at the car. You may check with MAFCA or MARC to see if there is a chapter near you. If you can find someone locally who really knows A's they can be a great help. Good Luck Jim

Thank you for your help. Theres a friend of the family who could help that knows these cars like the back of his hand but I try not to bug him as hes 90. He would be more than happy to help me out but I would hate to bother him

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  • 2 months later...

What type of Carb do you have? Zenith or Tillotson? It is likely that if the car has been sitting for a long period of time that there is a lot of sediment build up in the tank running into your system causing a blockage, that is especially a problem when your driving because it stirs up all the sediment. It may be wise to do a sytem flush if you see any small particles in the bottom of the carb when you disassemble it. If you would rather not play with the carb, you can send it to us, we will rebuild it to original specifications and send it back to you. Good luck, and drive safe!

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