To much fuel. 1923 35 Buick ?

[Barry R]

My 1923 35 4 cylinder Buick has a fuel problem.

She turns over nice and starts for few seconds then spluttering to  a stop.

won’t  re start.

There is fuel dripping out of air intake and when I pulled the plugs out they are wet.

 

so obviously to much fuel coming though. Is it the needle valve under the carb, or the spring pressure on the large thumb screw, or ?

[Oldtech]

Try disconnecting the line from the Vacuum tank to the manifold and start it. If it runs fine you have a problem in the vacuum tank- like a float that is no longer floating.  If no difference then you are likely looking at carb.

[Morgan Wright]

Once you remove the line from the manifold, pour a pint of gas into the filler plug on top of the vacuum tank. It's good for about 2 minutes on idle speed. You can use a tiny funnel that comes with whiskey flasks to pour the gas in.

[Mark Shaw]

Always do the simple fix first.

• Pull the lid off the float bowl and see if the float is stuck down or won't float enough to shut off the gas.

[Oldtech]

On 8/8/2022 at 5:40 AM, Morgan Wright said:

Once you remove the line from the manifold, pour a pint of gas into the filler plug on top of the vacuum tank. It's good for about 2 minutes on idle speed. You can use a tiny funnel that comes with whiskey flasks to pour the gas in.

If the tank is the culprit you won't have to put fuel in it. It will be full to the top. That's the problem.  Yes, by all means check the carb float too, 

Edited August 10, 2022 by Oldtech (see edit history)

[Morgan Wright]

42 minutes ago, Oldtech said:

If the tank is the culprit you won't have to put fuel in it. It will be full to the top. That's the problem.  Yes, by all means check the float too, 

 

True dat.

 

But, and I haven't done the experiment, I think if the valve in the vacuum tank which controls the manifold vacuum line doesn't shut off when the float is at the top, and the engine is running, the manifold will suck the gas directly in from the vacuum tank and bypass the carburetor, suck at least half the contents of the vacuum tank into the engine. With no needle valve or idle adjustment screw to control the gas, it will suck a huge amount of gas in, probably half the contents of the vacuum tank, which is around 1 pint and a few ounces. I think when you take the manifold line off, the vacuum tank will not be full to the top, it's good to get the vacuum tank full again, because the manifold line is off and can't refill it.

[michealbernal]

I had then exact same problem with the vacuum fuel system on my 1928 Standard.  I turned out to be an almost microscopic paint chip lodged in the tank valve.  I only found it with a magnifying glass

[Oldtech]

22 hours ago, Morgan Wright said:

 

True dat.

 

But, and I haven't done the experiment, I think if the valve in the vacuum tank which controls the manifold vacuum line doesn't shut off when the float is at the top, and the engine is running, the manifold will suck the gas directly in from the vacuum tank and bypass the carburetor, suck at least half the contents of the vacuum tank into the engine. With no needle valve or idle adjustment screw to control the gas, it will suck a huge amount of gas in, probably half the contents of the vacuum tank, which is around 1 pint and a few ounces. I think when you take the manifold line off, the vacuum tank will not be full to the top, it's good to get the vacuum tank full again, because the manifold line is off and can't refill it.

You may be right but there is SUPPOSED to be an orifice fitting in the vacuum line so that it can't just slurp half the tank in. They can actually run - horribly, but run on the gas from the vacuum line

[Morgan Wright]

I take back what I said.

 

If the valve in the vacuum tank which controls the manifold vacuum is defective, and doesn't shut off the vacuum when the float is up, and the valve which controls the atmosphere is not defective, and opens to the atmosphere when the float is up as it's supposed to, that means that when the float is up and the defective manifold valve allows fuel to flood into the engine, it will be stopped by all the air that comes in the atmosphere line and breaks the suction, so the manifold line will stop sucking gas in, and will only suck atmosphere in. I took this picture of my car just now:

 

 

 

Edited August 10, 2022 by Morgan Wright (see edit history)

[Oldtech]

I was thinking the float had a crack and was sitting on the bottom. 

[Barry R]

Thanks guys,

Since I first posted my question I have been  messing around with the carb adjustments. With no luck.

now I’ve read the reply’s I’ll go check the vacuum cylinder.

 

what should the settings on the carb be?

[Fred Rawling]

This is how I check the vacuum tak valve to see if it is leaking.

 

Remove the top of the vacuum tank.  Put a rubber hose on the vent line and with the float down (valve closed) blow in the tube. You should not be able to blow through the valve'.  Float up you an blowe throigh it easily.

 

Move that vent fitting with the tube on it to the vacuum line  opening.  With the float up the valve should be closed.

 

If you find a problem you can try lappiing the valves with some toothpast thined with water  or brass polishing impound thined in solvent.

Fred Rawling

Bellflower, Ca