Re: Autolite Dizzy - Vacuum advance shot

Posted by Owen_Dyneto On 2015/4/30 15:10:25

Failure of the vacuum advance diaphragm results in stumble or hesitation on acceleration, plus of course the ongoing problems of an open vacuum leak - lean mixture, perhaps overheating, etc.. NOS units for most Packards are pretty much extinct and even if you found one it may well give a very short service life as the rubber is often age-deteriorated. Rebuilt units are available from Max Merritt and perhaps from Kanter Auto Parts. I won't say it's impossible to repair yourself, I have at least one friend who has done so, though I don't know how well it performed. You'll need the rubber diaphragm material more or less equal to the original in physical properties and to install it you'll have to open the metal crimp on the container and then reseal it later, plus whatever is required to attach the actuating arm to the diaphragm. And if you go that route you should try to get the distributor on a test machine and make whatever adjustments are needed (springs and shims) to match the OEM specification for degrees of movement versus applied vacuum.