engine and drivetrain Problem diagnosis

[Chris_B]

How often does this problem occur? Have you tried adjusting the idle mixture on the carb? What is the normal idle speed after the motor is warmed up?

Note that your carb has a bowl that holds fuel to provide a buffer for times when the flow may be low (e.g., at idle). A full bowl will allow the motor to idle for quite a while, so fuel supply problems are not likely the cause of your motor dying when coming to a stop, if you don't have any other running problems with the motor while driving. However, that doesn't mean your problem is not being caused by lack of fuel.

You may have an obstruction in the idle circuit of the carb. Also, do you know whether your carb has an idle solenoid (if so, you would see an electrical wire running the right side of the carb).

[TobyB]

I'd check the float level next...

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[mike472]

Did you use a dwell meter to set your points? Did you set the timing with a timing light to check ignition timing and whether your distributor advances properly?

Did you tighten the lines on your fuel pump and filter enough? You may be sucking air in at those hose connections causing momentary starvation at low speeds. Your fuel pump may be struggling to pull enough through the line at idle yet run OK with your foot on the throttle. If you just changed the filter I would check the connections on that too. Air can enter either place causing the pump to suck enough air bubbles in to starve the engine's fuel supply. You might think you would see a leak, but not always.

Another problem might be some gunk in the bottom of your carb float bowl. Definitely take the top of the carb and take a look. If you don't use the car that often and the fuel tends to sit for a while you will find that gas will form a dark brown gunk that will be at the bottom of your float bowl. That may be partially blocking the jet down there. This is a common problem on any engine that sits a long period of time without a fresh refill of fuel.

[Chris_B]

The carb depends on gravity and vacuum from the intake, not fuel pressure from the input, to provide fuel from the bowel. For my own edification, how does low input low at idle make a difference, if you have any fuel the bowl?

[Deutschman]

I work all tomorrow so i wont have time for my car, but I am going to make a list of all this and check it out Sunday, and get back to you guys.

Thanks again!

[c.d.iesel]

dirty idle jet circuit

dirty primary jet circuit

missing / broken idle jet seals

loose carb mounting - or leaking carb base gasket

float level

[mike472]

It depends on vacuum to pull fuel through the jets and passages in the carb. If the fuel level drops in the bowl it will not run right.

[carlkkreienkamp]

+1 on the idle jet circuit. Listen to C. D.