Topic: carbie problems


ians34    -- 01-10-2010 @ 2:26 AM
  good evening all, I have a small problem with my 34 ford, I have just got the engine going after fitting a new fuel pump from Macs. My problem is that the carbie is overflowing at idle from the accel plunger hole on the top of the carbie. If I give it a rev it clears up until I drop back to idle again. I had a spare 97 so I ran a kit through it , checked the float level, fitted it and bugger me its doing it too. Could the fuel pump be providing too much flow/pressure. What pressure should I have. Any clues, your help would be appreciatted, Regards Ian from West Australia


flathead4rd    -- 01-10-2010 @ 6:00 AM
  Sounds like a fuel pressure problem. If you are using a stromberg carb you need to keep the fuel pressure at less than 2-1/2 lbs. I run mine at 1-1/2. Get a fuel pressure regulator.


TomO    -- 01-11-2010 @ 9:09 AM
  The fuel pump should not provide more than 3 lbs pressure. Typically they provide 1 1/2 to 2 1/ lbs. If it is more than 3 lbs, you can reduce the pressure by replacing the diaphragm return spring with one with less tension.

You should also check your floats for leaks by placing them in water that is at boiling temperature and looking for small bubbles coming from the float.

Tom


37RAGTOPMAN    -- 01-11-2010 @ 5:38 PM
  HI
try removing the needle and seat,make sure there is no dirt in it, it may not be shutting the fuel off, and overflowing the carb,,
you might have distrubed something and it got caught in the needle and seat, these just unscrew from the outside of the carb, a 5 minute fix,
you could also. remove one of the plugs in the front of the carb, put a clean paper towel under the plug when removing and see if dirt comes out, when you drain it,
before the fuel pump replacement how was it working,?
is it different now,?
just my 2 cents, 37 RAGTOPMAN
also check fuel pump pressure,



ians34    -- 01-19-2010 @ 1:10 AM
  well guys. I tried everything , I even made a gasket 3mm thick and than d*mn thing still pumps fuel out. I gave up and went down to the local parts shop and bought an adjustable low pressure valve. I will try that this weekend and let you know. Isn't working on cars supposed to be fun?



TomO    -- 01-19-2010 @ 6:47 AM
  Did you check your fuel pump pressure with your vacuum gauge? What was the pressure? The adjustable pressure valves add another layer of complexity to your fuel system. I have seen them leak, shut down fuel delivery, and cause high speed (45mph+) miss.

They are necessary when you have an electric fuel pump that delivers more than 3 lbs of pressure.

Tom


39 Ken    -- 01-19-2010 @ 9:27 AM
  May be that the carburator float is too high and not closing off the fuel. Did you try lowering the float?


ians34    -- 01-24-2010 @ 10:55 PM
  The on going saga of my flooding carbie, I purchased an adjustable low pressure valve (not a Holley) of Ebay and fitted it up. Of course it didn't work and still flooded . No matter which pressure I set the valve at including .5lb it made no differance. I have now ordered a Holley unit. I will try that and see how I go. Stay tuned for more adventures.


TomO    -- 01-25-2010 @ 7:30 AM
  Did you check your float by placing it in boiling water? The bubbles will be very small and will probably come up near a seam in the float.

Your problem sounds like a leaky float, binding float, incorrect float level or a defective needle valve.

I would remove the top of the carburetor after the engine has been idling and check the fuel level. It should be between 17/32" and 15/32" from the gasket surface of the fuel bowl. I like to set it at 17/32" with a new needle valve as it will rise slightly as the valve wears.

Tom


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