223 I-6 carb flooding

[Daves55Courier]

The Holley 1904 carb is acting up again. About ready to throw in the towel on this 223 engine. Gas is spilling out of the air bleed tube from the float chamber into the carb throat. I took the float chamber cover off and it appears that the float is adjusted lower than the factory setting when I lift it up with my finger. The float moves very freely and there is no force required to move it up with my finger. At its highest position, the float is perfectly horizontal, which means that the gas level had to be above the top of the float to enter that air bleed tube. Its a new fuel pump. I just finished routing a new fuel line from the pump to the carb to get the fuel line further away from the engine to keep it cool and help eliminate vapor locking. Coincidently the flooding began immediately. The new fuel line is shorter than the original one. How much pressure should there be from the fuel pump at idle ?

 

[Anonymous]

is that a galss bowl? i would just tweek the float adjustment a bitso it shutt off a bit sooner. did this happen after the new line?

 

[Daves55Courier]

I went back and took that carb off and installed a NOS Holley 1904 never installed on a car before. I let it idle for 15 minutes and checked for leaks. Everything seemed fine. Then I drove it down the block and got out to adjust the Fordomatic passing gear link. When I opened the hood, gas was pouring out of the vent hole in the top of the float chamber.

Got back home in it and shut it off. Gas poured down the throat for at least ten more minutes after shutting it off and I could hear gas boiling in the bottom of the intake.

This really bites. This is now the 4th carb I've installed on this thing in a few weeks, but it wasnt flooding until after I installed a new fuel line from the pump to the carb. The new line has 3 fewer 90 degree bends than the original one did and is a few inches shorter.

 

[addo]

What's probably happening, is that the seat pressure (equated to psi) of the inlet needle in your carby, is now being overridden by the pump pressure. A shorter fuel feed with less restrictions could cause this.

If you can bear it (unoriginal), install a return type pressure regulator with return routed to the pump infeed side. A non-return regulator may well creep up at idle.

Regards, Adam.

 

[Anonymous]

put a fuel pressure guage on it!
These carbs are very touchy. at WOT it takes about 5 lbs but at idle they do what you describe at 1.5 lbs. Ive been through about 8 carbs on my 3 x 1 set up before i got it running good so that it wouldnt flood at idle. Im just telling you what i went through. It took me 3 months to get mine running how i wanted it. Just relax and play with it. Youll be happy when its up and running how it should be.

Good luck.

 

[Fred]

These carbs are also very touchy about crud in the fuel. If you get a bit of junk between the needle and seat, it will flood. Make sure you have a clean gas tank and a good fuel filter.