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Quick start with carburetor equipped fuel system

Discussion in 'Non-Mopar Tech Support' started by AllanC, Jun 4, 2020.

  1. AllanC

    AllanC Well-Known Member

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    I have been wondering that before the advent of modern fuel injection delivery systems on automotive engines, how vehicle engines were first started at the end of the automotive assembly line. Years ago engines used carburetors and the entire fuel system would be dry. If the fuel system were not primed in some fashion it would probably take 30 seconds of starter engagement spinning the engine to get sufficient fuel into the carburetor so the engine would start and vehicle driven from the assembly line.

    I am thinking that several pounds of air pressure were applied at the fuel tank filler neck. This pressure would force fuel through the line, through the fuel pump and filter and into the carburetor float bowl. The bowl chamber would fill with gasoline and then the float would rise and stop fuel entry at the designed fuel level. With a full float chamber then a quick, cold start would be possible. But this is a guess on my part. Does anyone know exactly how carburetor equipped vehicle fuel systems were primed on the assembly line.
     
  2. 85lebaront2

    Level 2 Supporter

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    Damn good question, I toured the now closed Ford Norfolk Assembly plant several times, I do not remember how they primed the fuel system at the end of the line. There is somewhere a YouTube video of that plant's assembly line as it had the world wide best quality record of all Ford assembly plants. Maybe there is something in that that shows it, but I don't remember it.
     
  3. valiant67

    valiant67 ...

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    I don't remember the details, but I think I've read how this was accomplished at Chrysler.
     
  4. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    My boss was a grunt at a GM plant right out of high school. I can ask him if he knows.
     
  5. KOG

    KOG KOG

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    Easy way would be a squirt down the carb throat. That or they prefilled the bowl through the bowl vent after the carb was bolted on.
     
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  6. AllanC

    AllanC Well-Known Member

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    An initial small charge of fuel down the carburetor throat would give a quick start. But that would last at most 1 - 2 seconds and then the engine would die. The engine would not run long enough for the mechanical pump to draw fuel through the lines, push it into and through the fuel filter and fill the float bowl. Then the engine would require a prolonged period of starter engagement to prime the fuel system and allow it to run.

    Seems that this would be a workable solution.
     
  7. GLHS60

    GLHS60 Well-Known Member

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    Interesting question.

    "Finally the headlights are adjusted, the wheels are aligned and gasoline is pumped into the fuel tank and thus another new vehicle is driven off the line under its own power"

    Thanks
    Randy




    https://books.google.ca/books?id=DmbsAAAAMAAJ&pg=SA11-PA299&lpg=SA11-PA299&dq=auto+assembly+line+when+is+fuel+added&source=bl&ots=Jz9B5VMF9j&sig=ACfU3U37VjYyRo465pumhQhzn6fUTx79wg&hl=en&sa=X&ved=2ahUKEwjv9PHMj-npAhWbCTQIHXpGBqEQ6AEwEnoECAgQAQ#v=onepage&q=auto assembly line when is fuel added&f=false
     
  8. Handy_Cruiser

    Level 2 Supporter

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    I believe that about half a shot glass of fuel will prime many carbureted engines. I still have one old Chevy truck that needs a gulp of fuel like this when I start it once a year. Of course, it likely still has some fuel in the lines. But I've started many engines with new carbs, fuel pumps and new fuel lines. It doesn't take very long once the engine runs.
     
  9. 68RT

    68RT Well-Known Member

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    It was common in days of your to put air to the tank to push gas forward. It only takes about a pound or two to force gas into the carb. I was taught the correct following way to do a starting a rebuild:
    1) Do not put the plugs in.
    2) Fill all fluids
    3) After checking for leaks, crank the starter until you see oil pressure. (No plugs in makes the load light on starter)
    4) Recheck for leaks and install plugs.
    5) Twice floor the throttle which will pump gas in and set the choke (carb should be full from prior cranking).
    6) Start engine and monitor for problems. It should be at high idle (part of choke settings) and touch throttle lightly in a few minutes as choke heats to bring down to low idle which can be set along with final timing (usually within 2-3 degrees of proper because we were taught how to set before first firing)
    7) Finish finals details and was the car and vacuum the interior for complete customer satisfaction.
     
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  10. valiant67

    valiant67 ...

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    It would be better to spin the oil pump (before installing the distributor) to build oil pressure. Then rotate the engine part way and repeat.
     
  11. 68RT

    68RT Well-Known Member

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    A'll parts had been given a prelub prior to installation. Oil filter was given a prefill to. Not all cars can have a pump spin due to gear being on the pump or distributor not closing an oil passage when out.
     
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