Carburetor Problems

Muttley

Muttley

Senior Member
The other night Dad went for a drive when the Coupe started running poorly and sputtering. This morning we added some Sea Foam to the tank, fired it up and let it run for about ten minutes. He took it for a ride around the neighborhood, and it started sputtering and died. The car fired up and he idled home with almost no power. We fired it up again and it will idle decently but when you give it gas it pops out of the carb. I shut it off and while we were discussing rebuliding it I noticed gas dripping from the carb throat and on to the top of the wishbone. Are we looking at a rebulild? I've never rebuilt a carburetor of any kind, how tough of a job is this on a stock Model A?
 
If it is a zenith just undo the bolt that holds the two halves together and see if there is debris in it. if so take the rest off the manifold and give it a good cleaning. dripping is caused by dirt holding the needle valve open or the float isn't floating well.
 
Does opening the GAV [ turn choke rod counter clockwise 1/2 turn or so] help ?? Is the carburetor getting good fuel flow ?? Try removing the fuel cap.. Is this something that has just happened or has the car not been operated in a long time ?? Has anything recently been done ?? Has the ignition system been checked and is the spark lever being used correctly ??
 
Sounds like the float valve is staying open and flooding the carburetor. The float may have come un-hinged. Drop the bottom casting off and check the float action. You shold be able to hold the float closed with your fingers and have someone open the fuel valve and there should be no leakage. Check that the float has not sprung a leak and filled with gas and sunk to the bottom leaving the valve open instead of controlling it.

Tom Endy
 
J Franklin said:
If it is a Zenith just undo the bolt that holds the two halves together and see if there is debris in it. if so take the rest off the manifold and give it a good cleaning. dripping is caused by dirt holding the needle valve open or the float isn't floating well.
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Truthfully, I dont know what model it is. It says "MODEL" on the side and has a rectangle with an X in it. The rectangle looks like it should have some other numbers but it doesnt. Here's a pic:

Carb.jpg


Patrick L. said:
Does opening the GAV (turn choke rod counter clockwise 1/2 turn or so) help?
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When I closed it completely it started to die (it didnt do that before).


Patrick L. said:
Is the carburetor getting good fuel flow?
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It seems to be but I cant be positive. The car also wanted to die when I pushed harder on the gas pedal (nearly to the floor).


Patrick L. said:
Try removing the fuel cap.
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I'll give that a shot tomorrow and report back.


Patrick L. said:
Is this something that has just happened or has the car not been operated in a long time?
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This is something new, the car had been running fine up until Friday night.


Patrick L. said:
Has anything recently been done?
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No, there have been no recent changes to the car.


Patrick L. said:
Has the ignition system been checked?
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Checked how? I just finished changing out the distributor cap, it was cracked and was arcing. It ran better after changing the cap out but its still sputtering and leaking (yes I know the cap has nothing to do with a fuel leak :rolleyes: :D).


Patrick L. said:
.......is the spark lever being used correctly?
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Neither Dad or myself have ever owned a stock Model A before so he is just going by the advice I've read here and on other sites. He starts the car with the GAV about 3/4 of a turn open and the spark rod all the way down. He usually keeps the spark rod all the way at the bottom while driving. I still havent been able to find the proper way to adjust the spark rod while the car is going down the road.
 
Last edited:
"the spark rod all the way down. He usually keeps the spark rod all the way at the bottom while driving."

This could be part of the problem, need to read the owners manual on using the spark lever.

Bob
 
Were fresh out of manuals around here.............I'm guessing the original owner tossed it sometime in the '30's. :rolleyes: Any way you could clue me in on how it should be monkeyed with to get it running correctly?
 
Muttley said:
Were fresh out of manuals around here.............I'm guessing the original owner tossed it sometime in the '30's. :rolleyes: Any way you could clue me in on how it should be monkeyed with to get it running correctly?
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Due to a whole bunch of varables the easiest way seems to be, start the car all the way up, As you drive lower the lever a little and you will notice the speed of the engine will increase. At crusing speed lower the lever a little more until the engine speed no longer increases and stop there.

This may help as well, just found it;

http://www.motormayhem.net/mode-a-ford-refrence-sheet/owners-manual/
 
It is the opposite Muttley. If you leave the spark advanced(down) when you start it, it can kick back and bend the armature or break the bendix. Always start the car in the up (retarded) position. Good luck Muttley
 
Muttley, it might be a vent problem with the gas cap. Start it up and run the engine until it starts to sputter, then unscrew the gas cap and see if that smooths it out. If the cap is venting poorly it will idle, but when you drive it will not allow enough gas fast enough to keep you going
 
Ed Saniewski said:
Muttley, it might be a vent problem with the gas cap. Start it up and run the engine until it starts to sputter, then unscrew the gas cap and see if that smooths it out. If the cap is venting poorly it will idle, but when you drive it will not allow enough gas fast enough to keep you going.
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I'll give it a shot but that wouldnt explain the dripping gas from the carb throat............or would it?
 
I agree with Tom Endy, above. What you describe sounds like gradual flooding. Does it drip gasoline for a while after acting up? Fuel starvation results in similar symptoms, except for the popping you mentioned. Either way, a stuck float could be the cause. ... By the way, you have a Tillotson Model X carburetor.
 
J Franklin said:
If it is a zenith just undo the bolt that holds the two halves together and see if there is debris in it. if so take the rest off the manifold and give it a good cleaning. dripping is caused by dirt holding the needle valve open or the float isn't floating well.
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BILL WILLIAMSON said:
How come no one suggested "tap gently on top front of carb"????
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I agree with the first and last response--this is where to start, especially if you haven't changed anything else. Sounds like dirt coming down from the gas tank has stuck the float and possibly blocked a jet. Take the carb apart and look in the bowl and look in the sediment bowl on the firewall for signs of a dirty gas tank. You might be in for a project cleaning it out, or maybe you'll be lucky and it's just an occasional thing.

Bill's suggestion might fix the sticky float. An easy way to clear blocked idle jet is to momentarily race the motor while momentarily popping the palm of your other hand over the carb's air intake. The tremendous vacuum due to racing motor with intake blocked WILL suck any blockage on through.

Steve
 
If you have junk in the float needle and seat, try running the engine with the tank valve closed until the engine dies. This will lower the float and may allow the inrush of gas to flush the junk out.
 
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