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forestb · 11-01-2020, 02:57 PM

Yes you caught me in time. Keep in mind that the ported port is where my vacuum advance is connected to. So I had to disconnect my vacuum advance to do this. I set the idle to 700 rpm in park and the vacuum read 12 pounds. I shifted into reverse and the rpms dropped to 600 and the vacuum dropped to 8 pounds.

11-01-2020, 02:57 PM	#41
forestb Registered User Join Date: Jan 2009 Location: Burbank, CA Posts: 3,584	Re: Spark plug diagnosis Yes you caught me in time. Keep in mind that the ported port is where my vacuum advance is connected to. So I had to disconnect my vacuum advance to do this. I set the idle to 700 rpm in park and the vacuum read 12 pounds. I shifted into reverse and the rpms dropped to 600 and the vacuum dropped to 8 pounds.