Holley flooding

[Not A Midget]

Wasn't sure if 5.0/5.8 Engine-Stock was the place for this so I came here.

Anyone here have some good experience with Holley carbs?
I've always had the problem of rough idle when the engine is cold, once it starts getting cold out, but this morning the car just would not idle at all, was getting flooded like crazy.

Tonight I've found out that the Boosters are leaking fuel into the carb at idle and low RPM.
Even when the engine is off, they are still dripping a bit, for 10-15 seconds.

What could be the cause of this, for it to just suddenly happen? I'm thinking maybe power valve somehow.
Other pages online, say float level is too high, but I've never adjusted the floats in the 3 years I've had the carb on the engine.

Pic related, you can even see fuel sitting on the throttle plate

[DerekTheGreat]

Your float is sticking, which is allowing fuel to flow past the seat/needle thing and pressurize the whole bowl which causes fuel to spew out of the venturies. Try whapping the bowl a few good times with a plastic handled screw driver or small rubber mallet. Always did the trick for me.

[Tiggie]

Dirt likes to get in there and hang up the needle and seat too. As Derek suggests, give it a love tap to see if it fixes the problem. If not, investigate why the floats are out of wack and/or the needle valve isn’t closing.

I’ve had needle valves fail before. Usually starts as really really easy starting - like EFI starting. Then gets worse like the flooding you are experiencing.

[jaywish]

Yup. Replace needle and seat. Make sure float is good and adjusted.

I rebuilt an outboard carb without finding the problem too many times. Finally I bought a float & found the plastic float had changed weight over the years.

[Not A Midget]

Alright, I did wack on the fuel bowl with a screwdriver handle a few times last night and it didn't do anything, I'll take the fuel bowl off this morning and check out the float, make sure it hasn't sunk. I'll get a new needle valve as well today

[DerekTheGreat]

Sometimes you gotta whap 'em pretty hard, top & side. Seat wearing out or the float sinking is a possibility as well.

[turbo2256b]

Carb has a site plug on the side of the bowl. to check level run engine shut it off unscrew site plug fuel level should be just even to a tad below bottom of plug hole.
If bowel is off turn the bowel upside down the top surface of the float should be parallel to the top of the bowel. After reassembly check float level as described above.

MOST COMMON REASONS FOR fuel out the vents
Brass or plastic floats leaking check to see hear fuel sloshing around in float
If it has the what I call foam floats many of then can end up sucking up fuel and cant tell if weight has gone up without triple beams.
Suggest replacing foam floats with brass ones

[jaywish]

Nice to know they still have the sight plugs. I forgot that Holley had them. It was a really nice feature.

[His Royal Ghostliness]

They have sight glass now, not plugs, don't have to remove anything to check fuel level. Also those big brass screws with the jam nuts there by the fuel inlets to the bowls in the OP's picture are the external float adjustment IIRC, again so you don't have to remove anything and have gas leaking all over the place. Old Holleys had neither of those things, they were real fun to work on, not!

[turbo2256b]

Holley has clear plastic site plugs but with today's fuel the go bad back in the day you could leave them in. Some carbs like the quick fuel have glass site plugs

[His Royal Ghostliness]

I remember the glass ones, hell if I know what Holley that was I was dealing with at the time, I just assumed they all had glass ones. I've been out of that game for a while now tho, and don't plan on getting back into it - anything I'm interested in that could use a carb would do better with a light diesel, and nowadays it's pretty easy to set up a nice 6.2 with upgraded block and full mechanical injection and boost and get decent power and excellent fuel economy out of it. Still would tinker with a carb if one came along, but would not willingly install one where there was none to begin with, lol

[Not A Midget]

Carb has a site plug on the side of the bowl. to check level run engine shut it off unscrew site plug fuel level should be just even to a tad below bottom of plug hole.
If bowel is off turn the bowel upside down the top surface of the float should be parallel to the top of the bowel. After reassembly check float level as described above.

MOST COMMON REASONS FOR fuel out the vents
Brass or plastic floats leaking check to see hear fuel sloshing around in float
If it has the what I call foam floats many of then can end up sucking up fuel and cant tell if weight has gone up without triple beams.
Suggest replacing foam floats with brass ones

I don't have fuel coming out of the vent tubes, I have fuel dripping out of the booster venturis. My float wasn't sunk, nice and empty and it floats. I cleaned out the metering block at work, bought a rebuild kit and put in the new accelerator pump, Power valve and needle and seat. If somehow that doesn't fix it, then I'll just rebuild the whole carb on Saturday

[Not A Midget]

Now the car won't even run, just bogs out and dies. I don't know why it would do this

[jaywish]

Did you adjust the float level?

[Not A Midget]

I adjusted it so it was parallel with the fuel bowl when inverted. Feels like it's missing hard now.

Spark plugs might be too fouled now. when I was doing a compression test last night, all the spark plugs were black as could be and reeked of gas, since I was flooding. I'll get some new plugs tomorrow

Also, cleaning the metering block, fuel bowl, then replacing the needle and seat and power valve has stopped gas from dripping out of the boosters. One problem fixed, another new one to fix I guess