I inadvertently hooked my distributor up to manifold vacuum once and could not get idle speed to set right. as manifold vacuum went up so did my idle speed, so I'd back off the adjustment and vacuum would drop killing idle speed, took me a bit to figure out what was going on. Never could get it set right till I hooked up to ported vacuum.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
