280Z Running Rich - Fouling Plugs - HELP!!

[Captain Obvious]

It's really hard to evaluate using a recorded media like that, but I don't like the sound of it either. The frequency is too high. I can deal with a "tap" at idle, but it's almost a "buzz". I'm thinking alternator bearings or brushes?

Or, it could just be impossible to tell from a recording like that. 

[Zed Head]

I get a distinct sense of rocker arms tapping on cam lobes... who knows.

Here's a sound for comparison - 

 

[rcb280z]

I have a Bose system, bass speaker with 2 surround speakers. Sound is wonderful.

I'm curious, have you reversed the two connectors mentioned above yet?

[Jdizz07]

Thanks for the replies everyone.

Haven’t had a chance to get to the old girl this week as it’s out at my lockup (problem in London having no garage!), will have a tinker this weekend on all the above possibilities and get back to you. Really appreciate the help and will be in touch over the weekend. 

JD

[EuroDat]

When you get this problem solved, replace the Champion plugs with NGK's. You will notice the difference.

Edited May 25, 2018 by EuroDat