vacuum advance
 

How far out should my vacuum advance canister move? I was told by a mechanic that my distributor needed some work, such as a worn distributor shaft, and I'm curious what all I need to do to the distributor to make the car run in tip top shape. I've been told by other Z aficionados that the vaccum advance canister can be a huge cause of problems, because they will seize up after a while.

I attached a length of tube to the advance canister, and I sucked on the end of the tube, and the vacuum advance moved about 1 mm. and no more. How much should it move for it to be good?

Also, what other parts are common to go out in the Z distributor?

If you're on the original dizzy, it's prolly getting time for a new one. You tested the vaccum advance the correct way. I'd guees that the shaft should move closer to a 1/4" (6mm +) or more. Your fsm should tell you what the timing advance (in degrees) should be and you'd check it with a timing light. You have static timing at idle and then you rev the motor up to 2k (or so) rpm and then you have a different value.

The parts that wear our are the drive gear, the bronze shaft bearings, the oil seals, and the vaccum advance diaphragm. A worn out dizzy can have a HUGE impact on how well your motor runs. I'd also assume that it's been converted from points to electronic pickup. If not, then the lobes that the points run on will also be worn out. If so, you can always set the proper point gap, but you won't have the proper dwell.

yeah, I have a pertronix electronic points kit.

Your dizzy also has a mechanical advance. It can give you an advance at higher rpm but the vacuum gives it advance when you first press on the gas. The best way to check it is with a vacuum pump/gauge so you can check the movement of the breaker plate with the engine off. I use one to bleed my brakes and clutch too. You can buy one for about $20-$30, a very useful tool. You can also check by observing the timing mark and at idle and have someone hit the gas. If your vacuum is working you should have instant advance at low rpm. Take your dist cap off and move the rotor shat side to side. You should have very little visible side play. If it moves then more than a hair then your dizzy needs replaced.