Re: 29 packard carb problems

Posted by Tim Cole On 2011/11/30 18:41:39
Dear 29:

Let's look at how this carburetor works. The tube in the throat of which you speak is the fuel jet. The design does not have an idle circuit, power valve, nor an accelerator pump. So if the fuel jet gets clogged the car will not run.

Next, the only compensation for this very rudimentary approxmation is the secondary air intake. That is the toilet bowl looking thing on the front of the carburetor. This valve opens to lean the mixture during moderate throttle or cruise conditions.

Now if the motor won't run, the first step in isolating the carburetor is to remove the acorn nut on top of the fuel bowl and pull up on the float needle. If the carburetor floods then the problem is forward of the vacuum tank.

It takes a lot of dirt to clog the fuel jet and if that is what you found then it's time for some detective work.

A common culprit is seating problems in the vacuum tank and an easy test is to manually fill the tank to get the car running. There are two needle seats in the vacuum tank that cause problems picking up fuel because they become loose and don't seal. That can be fixed.

Usually dirt getting into the vacuum tank will cause engine shut down and in that case it's probably time to drop the tank and inspect the work done. If that sounds like too much work for starters, then try running the motor out of a gas can. If the car runs okay then you know the problem is behind the vacuum tank.

After that poor electrical connections from the ignition switch forward are also a common cause of motor shut down.

Hope this helps.

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