carb vac to dizzy

[Anonymous]

I was working on my car a while back (before I deployed) and I got to thinking lately about the carb and dizzy set up. Been doing a lot of tuning in my head.

I set the timing at about 10* BTDC with the vac line removed from the carb.

My question is...Why don't I see any idle change when I remove the vac line off the distributor from the carb? I realized doing that isn't changing the idle. Shouldn't it?

68 200 block in a 66 Convertible. Pony Carbs Autolite 1100 carb (with SCV)...dizzy with two vac take offs. I use the one on the end of the vac diaphtagm only.

I blocked the venturi that makes the SCV work with instruction from Pony Carbs as I have a non-scv dizzy.

Or maybe a bad dizzy? Thoughts?

 

[jamyers]

You should be getting vacuum to the dizzy diaphragm at idle...and the idle speed should change (drop) if you disconnect and plug the line.

When you disconnect the vacuum line, is it sucking air? If not, check the line and SCV valve for blockage.

If it is, try hooking up a long hose to the dizzy and sucking on the end, you should be able to get and hold enough vacuum to pull the diaphragm in and see the dist points plate move. If you can't get/hold vacuum, the diaphragm is leaking and needs replacing (kinda common). If you can get/hold vacuum but the dist points plate doesn't move, then something's hanging up inside the dizzy (kinda rare)