Mayaguez1022

So, I got an 86 IRoc with 305. Stock for the most part...Edlebrock performer intake and 600cfm edelbrokc carb. Swapped TPI out for carb bc of upkeep cost. New MSD Streetfire dizzy.

Here's the problem. Whenever I hook up my vacuum advance, the car knocks/pings or whatever, under load. With the vac advance off, the noise is gone. I do not know what to do. I don't want to leave it unplugged seeing its a daily driver and it would greatly affect my MPG. HELP!!

Apeiron

How much vacuum advance do you have, and when is it coming in?

For that matter, what does the centrifugal curve look like?

Mayaguez1022

I couldn't exactly tell ya. To be honest, Im not too familiar with timing curves and things relevant...as sad and stupid as it sounds. Maybe this is my problem. haha I know I've tried adjusting the vaccum canister with an allen wrench. I've tried the range from no turns to about ten turns out.
How do I find the centrifugal curve?

Apeiron

Adjusting the spring tension will change the rate of vacuum advance, but not the total amount. You could be running too much. I don't know if the MSD 8362 has a vacuum advance limiter.

Set up the centrifugal curve with MSD 8428. Start with the instructions here https://www.thirdgen.org/hei. Damon is talking about stock distributors there, but they work exactly the same way.