Tach needle goes to red and back on start up

[GPNVCAT]

Strangest thing happened today. Tach needle went to red and back to zero just before the starter engages. Now it does it every time. Not too big a deal, but why now?
Once it's running, no issues. MFI distributor, recalibrated tach, everything works except that goofy sweep just prior to start up.
Thanks in advance!

 

[spmdr]

The only time I have seen anything like that,

was a bad connection in the high current starter circuit,

causing the starter solenoid to chatter.

DW

 

[michael-king]

Strangest thing happened today. Tach needle went to red and back to zero just before the starter engages. Now it does it every time. Not too big a deal, but why now?
Once it's running, no issues. MFI distributor, recalibrated tach, everything works except that goofy sweep just prior to start up.
Thanks in advance!

I would guess a grounding issue perhaps to do with feed off igntion or with the starter.

As a side note.. it's now doing the modern start-up routine where the gauge needles dance to entertain people

 

[hottigr]

Is it possible it has been doing this since you had it recalibrated and you're just now noticing it? I tried one of the tach rebuilds with solid state guts- it would sweep the way you described every time the key was turned on. Unfortunately, it didn't like my mechanical dual-point distributor for whatever reason and wasn't accurate, so I had to return it...

 

[GPNVCAT]

It never did it until yesterday. It got recalibrated by Palo Alto Speedo and works perfect with the MFI distributor. I need to hunt for a loose ground or something. It’s not a bad thing and I do have an email sent to PAS. Will post what I find out.