Physically Impossible

Fuel and Air Systems

  1. Dana67Dart

    Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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    Can only share my personal experience.

    Stock 273 2bbl NO carb spacer, aftermarket stock mechanical fuel pump.

    If the car was driven yesterday 2 pumps and it will start on the first or second crank attempt and stay idling and drive no problem
    if it has been a week 2 shots, 2 crank attempts 2 shots and 1 or 2 more crank attempts and it will stay idling and drive no problem

    I have verified both ways that there is fuel in the accelerator shots both 2 shots and 4 shots worth.

    Fuel pump was last changed 2011 (100,000 miles ago) OEM fuel pump ran 163,000 miles


    I suspect that either the "it won't start crowd" are waiting months between starts, have a mechanical issue like a pinhole leak, check ball leak, or are so used to EFI that multiple crank attempts seems bad. Or maybe flooding it with too many pumps or too open a throttle or too closed a throttle or no choke or too much choke.

    Older ford 2 and 4 bbls had open vents to the fuel bowels (IIRC) and did not have evaporation issues. Yes fuel was different BUT if you are loosing 10% of the alcohol to evaporation you still have 90% of the bowl full. 2 inch tall bowl would be only 1/4 inch low and with only a few cranks it would be full unless the pump is sucking air.

    if you want to know for sure if it is evaporation, take a cup of fuel from your tank put in into an aluminum can and put it on top of your hot engines intake manifold after you shut it down. the next day see how far the level has dropped in the can. then you have PROOF that it is evaporation and not a leak. USE OBVIOUS SAFETY PRECAUTIONS WITH THIS TEST!

    These are my findings and opinion yours will be different, flame away if you want.
     
  2. Ottmundr

    Ottmundr 68 Fastback

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    I've been going back and forth on whether I ought to put in an electric fuel pump, or just stick with mechanical. I just had an idea for startups, I'll draw up a little diagram when I get home.
     
  3. Brooks James

    Brooks James VET, CPT, Huey Medevac Pilot FABO Gold Member

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    There is a qjet mod where you drill a hole at at the bottom of a paralell "walll"to get to another chamber, thus increasing the capacity.
     
  4. toolmanmike

    toolmanmike Moderator Staff Member FABO Gold Member

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    You can hear it boiling in the carb after a few min if you listen carefully.
     
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    • toolmanmike

      toolmanmike Moderator Staff Member FABO Gold Member

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      The electric charge pump is the slickest thing. Hook it up to a momentary switch, fill the carb, start the engine and go!

      electric fuel pump.jpg

      fuel pump.jpg
       
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      • royslead

        royslead Well-Known Member

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        That's not exactly breathing IN, is it?
         
      • CFD244

        CFD244 These pretzels are making me thirsty. FABO Gold Member

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        I had a 360 in my 86 conversion van. Whenever I stopped, I had to open the hood or it wouldn't start....Not to mention the goo from the back of the ECU dripping.......BTW, it had a Quadrajet.
         
      • Brooks James

        Brooks James VET, CPT, Huey Medevac Pilot FABO Gold Member

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        Yes go for it, redundancy, if one fails you have It covered
         
      • pishta

        pishta I know I'm right....

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        The facet style pusher pump can pump right through the mechanical pumps, and the mechanicals can pull right through the facet pumps. Once you try the $10 (ebay) facet style pump you wont understand why you kept pumping the carb (and killing the starter) for so long. flip it on, wait 5 seconds and its full. Wire it to the ignition switch so you dont even need to turn it on manually. Those facet pumps can support a 440 , all the motorhomes had them . IIRC someone told me a 70's Mopar had this same setup: Motorhome chassis, Hemi Dart?
         
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        • toolmanmike

          toolmanmike Moderator Staff Member FABO Gold Member

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          This kind.

          fuel pump.jpg
           
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          • missing linc

            missing linc Loose nut behind the wheel

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            My 76 Pontiac Ventura (40k original mile Oldsmobile 260 V8 with a Dualjet carb) needs to be pumped multiple times unless it's being driven daily. My wife is always worried that she will flood it, never happens though. I pump it several times before I start cranking, then while it cranks. Usually it will fire up after about 15 seconds of cranking, then stall after about 5 seconds, 2 more pumps and good to go. When it's being run daily, 1-2 pumps and fires right up. My Dart has been really good no matter how long it sits, 2-3 pumps and fires quickly, running an Edelbrock AVS2 with electric choke.
             
          • royslead

            royslead Well-Known Member

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            This is more symptomatic of "vapor" lock; and while it is evaporation, it is not the same as cold start issues due to potential fuel evaporating from the bowl, over time.
             
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            • toolmanmike

              toolmanmike Moderator Staff Member FABO Gold Member

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              Exactly. A carb spacer, and insulating fuel lines will help with vapor lock. That issue while the engine is running may need a fuel return type filter.
               
            • mechanicmark

              mechanicmark Well-Known Member

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              What's with this bullshit? Explain.
               
            • Dana67Dart

              Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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              Post #1


               
            • Dana67Dart

              Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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              Not to mention alcohol free gas!
               
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              • dirty white boy

                dirty white boy 50 yr old Juvenal delinquent

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                actually ethanol boils at bout 183 degrees, depending on atmospheric pressure...at least thats what g'pa said!
                 
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                • Bewy

                  Bewy Well-Known Member

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                  Two comments:
                  - I left some E10 in a metal tin overnight in the garage. Next morning, there were a few water globules about the size of rice grains in the bottom of the tin. I thought I had not properly cleaned out the tin....
                  So I completely cleaned the tin & left E10 in it again overnight. More water in it next morning. No E10 for me in carbed engines...
                  - Hard to start after standing overnight or after heat soak. The higher fractions of the fuel 'boil' off from the heat. What is left is less combustible & engine doesn't want to fire up.
                   
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                  • toolmanmike

                    toolmanmike Moderator Staff Member FABO Gold Member

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                    173.1. I'm thinking of all the junk that starts around 155° so they say. Even at 173°, E10 will boil in your carb. Cheers to G'pa!
                     
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                    • dirty white boy

                      dirty white boy 50 yr old Juvenal delinquent

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                      well,..takes 183 to keep a good steady stream a flowing,..so ive been told
                       
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                      • RustyRatRod

                        RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                        ....and this thread is proof positive you can't tell some people that.
                         
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                        • BadFishy

                          BadFishy New Member

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                          Hi, GREAT IDEA! I need this. Do you recall the brand and model you installed? Thank you.
                           
                        • Treblig

                          Treblig Well-Known Member

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                          No, it was a few years ago. Just make sure it's a "flow through" pump, they aren't expensive because you're not wanting a high pressure pump, just something to get the fuel to the carb. The flow through pump allows the engine mounted mechanical pump to pull gas through the electric pump after you start the car and shut off the electric pump. Also be sure and mount the electric pump as close to the gas tank as possible (this is important)!!!!
                           
                        • Captain Easy

                          Captain Easy Member

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                          Most folks have been driving fuel injected for so many years, if the engine doesn’t pop first rev or two, and immediately adjust the mixture to optimum, it feels like something is dead wrong. Some cabs, like some Rochesters, were pretty tight and would hold fuel in the bowl for a week or more if it wasn’t too hot. The Carters that came on a lot of the A Bodies were on the other end of the spectrum; let it sit a week or two and plan on nursing it: crank for 3-5 seconds, stop to let the starter cool for 10 seconds, repeat. On the 2nd or 3rd cycle, pump the gas pedal a few times to push some gas into the manifold, count to 10; take your foot off the gas and hit the starter. Sometimes you need to repeat the whole cycle a few more times. It’ll start. If you are really in a hurry, just put a couple tablespoons of gas in the carb throat, or the ultimate cheat, a couple squirts of starter fluid. Sorry, just is what it is. They acted that way when they were new. But when they were new, they were daily drivers, so generally there would be some gas in the bowl in the morning. If it’s a hobby car now, like mine, I can guarantee the bowl will have evaporated bone dry after a week or two. Car dealers would have lot boys go start everything in the morning for that reason, so buyers would get a nice quick start!
                           
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