Vacuum Advance Bad... How do I tell what Dizzy I have

[cvan1971man]

Think that we have a bad vacuum advance. I don't know how to tell what distributor I have.

I didnt know if it was possible to buy just the vacuum advance without buying the whole distributor.

If so, where could I source one? Can you buy them new rather than used? I have checked SOR, CCOT, Cruiser Teq.

 

[timmyisinthewell]

If it is a Toyota distributor it should have a part number on it to help you determine what you have.

 

[bhsdriller]

post a few pictures someone here will be able to tell

 

[wimberosa]

First...make sure its really a bad vacuum advance. Take the hose off the advance module port and with the cap
off apply 10+ inHG of vacuum. If there is no movement inside the dizzy and the port doesn't seem to want to
hold vacuum then the advance has a problem. You can do this with a cheapo vacuum tester like mityvac which
can also double as a huge help when you are bleeding the brakes.

All of the vacuum advance diaphragm modules are NLA as single units as far as I can find. Its possible to
split that apart and replace the diaphragm. On the inside is just a flat rubber impregnated cloth. The rubber
delaminates from the cloth or the cloth tears no longer holding vacuum. This diaphragm is really simple and
not specially "molded". I have some diaphragm material from a dental supply house that I'm investigating
as replacement (has not arrived yet). Splitting apart the advance module takes less than an hour with a small
screwdriver and hammer to lift the lip (and I had to split it twice since I have both carb port advance and HAC advance
ports). I'll publish how it turned out in my build thread soon.

 

[JohnnyC]

Are you sure you have an advance dizzy? You may have a retard dizzy

The picture posted above is a retard dizzy

 

[pb4ugo]

You don't need a special tool to check the advance canister. Put a hose on it and suck on it. If you can suck air, it's bad.

Are you sure you have an advance dizzy? You may have a retard dizzy

The picture posted above is a retard dizzy

That's not the OP's pic.

 

[JohnnyC]

That's not the OP's pic.

I know… he was shown an example of a vac retard dizzy

 

[Downey]

60061 and smaller last 5 digits is vacuum advance, 60062 and larger is vacuum retard.

 

[timmyisinthewell]

My only intent on posting the pic was to show the part number and location on the distributor. Sorry if I caused any confusion.

 

[Pighead]

Here, one's a vacuum advance and ones a vacuum retard...

 

[JohnnyC]

@timmyisinthewell

You’re all good… it’s good you posed it because if he has a vac retard it could be why he thinks it’s not advancing the timing … and if he has a vac retard that has a bad diaphragm I wouldn’t even bother to fix it

If the OP posted up why he thought it was bad or what it was doing to cause him to think it was bad or posted a pic of what he had then there would have been less confusion and would be able to get a more precise answer to what he was needing

Either way it’s all good on everyone… just kinda waiting on what the OP posts up next

 

[numby]

View attachment 4064474

The back of that pig might be kinda scary in a sudden stop.

 

[B y r o n]

Here, one's a vacuum advance and ones a vacuum retard...

View attachment 4064473

View attachment 4064474

These pictures make it easy to tell which type of vacuum advance/retard distributer you have. The vacuum canister can only pull when vacuum is applied. As you can see in the second photo, distributer on the right, the arm of the canister will pull the points plate counter-clockwise which will advance the timing. On the distributer on the left the vacuum canister arm will pull the points plate clockwise which will retard the timing.

This article will explain why they are needed.