Running Poorly
 

The odd thing to all of this is that when she first starts-up, it runs like a sewing machine however, after complete warm-up, the problems set-in for it begins missing and acts like it want to stall when staionary. In fact, it does stall when I stop at an intersection.

To begin my troubleshooting, I decided to adjust the idle speed as instructed by my Les Andrews manual. When I turned in the idle/air mixture screw clockwise, the motor did not stall rather I began to hear an air hiss from that area when the screw was momentarily seated. I backed it out about 1 1/2 turns and the air hiss went away. Is this normal for these carbs?

Other things I checked were possible leaks at the manifold and carburetor flange but did not get any rpm increase when I sprayed some brake cleaner around those areas. Also removed the gas cap just in case of fuel enting issues but that too did not make any difference. I am still learning about these cars but stumped as to why it runs poorly when warmed-up. Greatly appreciate any other things I should check. Steve

Re: Running Poorly
 

Idle mix adjustment is air, not fuel.

These carburetors are very simple. It sounds like you may need to adjust float level.

Re: Running Poorly
 

Try some Marvel Mystery Oil before doing any serious disassembly. Sounds like classic sluggish valves.

Re: Running Poorly
 

This shares a lot of symptoms with a problem that I had which was discussed extensively in this thread:
https://www.fordbarn.com/forum/showthread.php?t=261057
and then more in this thread:
https://www.fordbarn.com/forum/showthread.php?t=273571

At this point we think the problem is with the valves. I'm putting parts together to conduct a leak-down test. Check out the thread to see all the steps we went through.

Re: Running Poorly
 

could also be a condenser. check for a blue spark when it starts acting up.If yellowies red you have a bad condenser.

Re: Running Poorly
 

Appreciate the inputs and I tend to think it may be the valves for I had a similar situation on my 55 F100 223 straight 6 motor. Valve adjustment fixed it. Fired the Model A cold and ran great until the temperature reached 140 then beginning acting up again.

Re: Running Poorly
 

I agree with this. I had same problem and MMO did help. I took out spark plugs out and poured it in. Cleared up sluggish valve.

Re: Running Poorly
 

I have been adding 4 oz to the fuel during fill ups and was going to ask the best way to add for the valves and appreciate your guidance. Question- how many ozs per cylinder?

Re: Running Poorly
 

Condenser breakdown when hot.I agree with Mr Miller.

Re: Running Poorly
 

lift the spark plug straps just a hair off the top of the plugs and start it. Works best if you have a dimly lit area. Watch for steady blue spark, that will give you some good info as to look into spark or fuel. Not always easy to tell which is causing the problem.

Re: Running Poorly
 

Had to give my engine a good dose of MMO directly through the vacuum port on the intake manifold to free up the valves. Smoked big time but ran great afterward. Could probably shoot some MMO directly in the carb intake at elevated rpm. Might also confirm voltage to the coil is not dropping off by attaching a volt meter to the battery side and monitoring. When bad connections heat up the resistance goes up dramatically.

Re: Running Poorly
 

I vote for a new condenser. I had these same symptoms on my 6cyl F-1 a few years ago. Don't spend your time trying to see how hot the spark is. Bite the bullet! Condenser aren't very expensive!!

Re: Running Poorly
 

If you don't want to wait for an original condenser , a modern style condenser can be connected to the switch side of the coil . If original color coded wiring is used and the car is positive ground as original , the switch side of the coil will use a red wire . The condenser can be either connected to the firewall or the coil bracket for ground . A good clean tight ground where the condenser is mounted is important . I have used the last condenser that Ford used in 1970 on the V8 engines . This is the same condenser that the model A parts vendors sell for use with the V8 points setup . If the coil is going bad it will have similar symptoms as a condenser when it is going bad .

Re: Running Poorly
 

Update. Checked the spark when it started acting up and it was a nice crisp blue. Going to remove the carb and check and see if the float valve is sticking. I did notice that after I emptied the glass bowl to check for trash, when I got everything buttoned up and turned on the gas, it was also dripping out the bottom of the carburetor.

Re: Running Poorly
 

Perhaps not enough gas was getting to the engine because of the leak? Was there a puddle (though gas does evaporate quickly)?

Re: Running Poorly
 

The dripping was only temporary. I may turn the gas on and see if any seeps out. When it was running there was no leaks.

Re: Running Poorly
 

Update. Took the carb apart and discovered the float valve was a bit sticky. After cleaning all this and the other components, everything is good to go. Should have done this at the beginning. Lesson learned. Thanks for all the inputs. Steve.

Re: Running Poorly
 

Another vote for the Condenser