No longer idling at stop

M

Maurer1929

Member
My 1929 Fordor has been running very well since I put on a rebuilt carburetor (one of the ones sold on ebay). Once installed, I could slow down very fast for a stop light and it would maintain idle. Now when I am stopping at a stop light the engine dies...no idle. I would assume it is the carburetor but not sure what to check. Any ideas?
 
Sounds like the carb. I'd take it apart and check the float and double check and make sure everything is clean. Most likely if you have trash/dirt in your tank, it's favorite place to go is the carb.
 
i vaccuumed out my tank and tapped on a small screwdriver to loosen any rust, and put on a pressin filter on the shutoff
John
 
Maurer1929 said:
My 1929 Fordor has been running very well since I put on a rebuilt carburetor (one of the ones sold on ebay). Once installed, I could slow down very fast for a stop light and it would maintain idle. Now when I am stopping at a stop light the engine dies...no idle. I would assume it is the carburetor but not sure what to check. Any ideas?
Click to expand...

Is it possible that your idle screw moved from vibration. Try speeding it
up a hair and see if that makes any difference.

Tom.....
 
When an A dies after a quick stop it's usually that the float level is too low. But that fact that it was idling before and now it has stopped would point to other things. As already stated. Check the idle in the driveway. If it is idling ok then I would say that the other likely target is debris from the gas tank is makeing it's way into the carb. Easy enough to take apart and look around it won't be the size of pennies it will be very small. If you have an air compressor blow out the jets. It is very much a process of figuring out what it is not and that leading to what it is. Follow this link to a great collection of articles by Tom Endy on carbs.
 
Most of the time when the car suddenly starts dying on idle, the problem is a chunk of something has gotten lodged in the idle jet. There is an easy fix I think of as the Carburetor Heimlich.

Get the motor running in neutral in your driveway advancing the hand throttle as much as needed to keep it going. Open the carb-side hood. Take off air filter if you're using one. Put a glove on your left hand. With your right hand on the throttle rod, briefly rev the motor to high rpms while simultaneously clapping the palm of your gloved left hand over the carb intake. Quickly--before the motor dies--release the throttle rod and remove your hand from the carb intake.

What happens is that, with the intake blocked, all of the tremendous vacuum made by the revving motor is sucking on the poor little idle jet. You might have to repeat this a few times, but it WILL clear the blockage.

If you have to do this too often to suit you, then it's time to worry about the source of the dirt. Beware of trading your idle problem for a high speed problem by installing a fuel filter. IMO, they work best for folks whose system is so clean they don't need them.

Steve
 
I had this same problem, and discovered the cause to be the float hinge pin, which would slide out of position and partially free the float from its hinge.

When your car stalls, remove the lower half of the carb and check the position of the float. If it drops down at an angle, your hinge pin may be out of position.

The cure is to flatten one end of the pin in a vise and tap it into position through the carb hinge ear.

Of course, you should first check all the other items mentioned in the previous responses, as well as debris in the secondary well. I agree that vacuum leaks and incorrect float level are most often the cause of idle problems, but you report no problems with your old carb, or with the new one, initially, so you should suspect some issue which developed in the new one after a few miles of running.
 
Last edited:
I had similar symptoms after getting a re-built carb and found that the float had a very slow leak, but enough to cause it to sink and not idle correctly. Put a new float in and problem solved! Very easy to check!
 
You must log in or register to reply here.
Back
Top