Re: '41 super 8 stumbles on idle

Posted by Tim Cole On 2012/3/19 19:23:47

Dear Dan:

To determine the vacuum leak question just disconnect and plug the manifold side of the pump. Leave it that way until you solve the problem.

I assume the full throttle acceleration is good. But ignition problems can be examined with a spark tester (available form NAPA). You should have at least 20Kv at idle. Connect the unit to ground and not to the spark plug.

Now if too much fuel is the problem then manually opening the choke when cold should make the car run better, but it should also be belching black smoke.

If your idle air bleeds are clogged then spray choke cleaner into the carburetor, race the motor and momentarily put your hand over the carburetor. The suction will help clear the bleeds.

You say your motor vacuum is good so I would also check out the electrical on the primary side of the ignition. The amored cable likes to short out, but this whould be revealed in a full throttle acceleration. Ditto a shorted breaker plate.

Finally, don't discount a fuel problem. Packards burn a lot of gas so it's possible you bought some bad gas.

Hope this helps