Normal idle vacuum in neutral, A/C off should be about 16" @700. Never checked vacuum at the EZL vacuum signal line. If it's a "ported" vacuum advance (signal port above the throttle blade) there would be no vacuum at idle. Even if there is vacuum, I don't think the EZL adds any advance until the engine is above idle. Idle timing is fixed at 9 BTC.

What are your readings?

Duke