Pretty sure the tach signal is coming from the alternator on this motor.
Maybe check for a loose connection there?  It is the W terminal on the rear
of the alternator, not the main power hook up or the blue wire hook up.

Ken

On Thu, May 19, 2016 at 1:37 AM, Mike Miller <mwmiller6@att.net> wrote:

> Volks, and oil head Volks,
> Got a TDI conversion with a diesel cluster [Thanks again Roger!]
> The tach occasionally starts bouncing around from 0 to 4-5000 rpm. Tried
> lubing it but the problem reoccurs.
> Is there anyway the pick up [where ever it is and however it works] could
> have an intermittent problem?
> Any other ideas of stuff to try?
> TIA
> Mike from Cotati
>

--
Thanks,
Ken Wilford
John 3:16
www.vanagain.com