carb question

[48junktruck]

have a holley 3310 750 vacum secondaries. Im running an electric pump set at 4 psi or supposed to be and it does seem to be. Turn the pump on and after a few seconds when the rear bowl fills the gas flows out the rear vent tube. Checked the needle and seat and both are fine. Pulled the bowl and float seems fine. Am I missing something else? Truck runs great but even running when I turn the pump on its like a water cascade out the rear vent tube. Anybody?

 

[Rev Tex Devlle]

having simular problem myself, with a 5 psi fuel pump! the carb worked well on the truck with a mechanical fuel pump took the carb off and put it on the pontiac and now it floods, and i deas? anyone , didnt mean to hijack just lookin for answers too!

 

[rainman]

Have you actually tried adjusting the float level down while its running? If it still floods you may have to run a regulator. The pressure of electric pumps as stated are not very reliable.

 

[fuzz]

You may have to use a pressure gauge to see what pressure the pump is producing. 5 lbs isn't too much but 9 lbs is too much. But the obvious is that too much fuel is entering the float bowl because of high float adjustment, if memory serves the 3310 isn't externally adjustable, you have to remove the bowl and bend the "tang" on the float, or the needle and seat are allowing fuel to get thru because they are leaking and need to be replaced,or there may be a small spect of dirt under the seat.

 

[48junktruck]

mine is externally adjustable and ive tried multiple adjustments. Ive tried a different needle and seat and a different float bowl to no avail. I cant believe all is bad. Maybe I need the regulator. I do feed from the rear. Last thing I can try is to feed the front first and see if it does the same thing.

 

[fuzz]

I don't think feeding from the rear would make any difference. You need to check pressure with a gauge. I have seen float tangs bent to the point where they were beyond adjustment. Remove bowl and check float level.

 

[48junktruck]

this carb doesnt use the tang. It is externally adjustable.

 

[fuzz]

The external adjusting bolt pushes against a tang on the float. Take the bowl off and look at the place where the adjusting bolt touces the float. If it is bent you can screw that adjusting bolt all day long and won't get the proper adjustment.

 

[fuzz]

Just had another idea. If the float gets a hole in it, it can get fuel inside and won't float and will give you the same problem. You have to remove the float to check it.