Tach Bounces while Shifting

[240260280z]

This is pretty much an educated guess: I think the 100uF cap in the circuit could be kaput and the diode/cap "tank circuit" is not working. Transients (back emf) on the tach's anemeter are not dampened correctly when going from higher rpm to lower rpm during a gear change.

[240260280z]

OR it could be a broken spring in the needle assembly

Read this great write up: http://www.classictiger.com/techtips/motach.html

[240260280]

73 240z Tach Circuit Schematic

 

[jalexquijano]

On 1/4/2018 at 8:58 PM, 240260280 said:

73 240z Tach Circuit Schematic

 

I recenly replaced my 4 year old battery with a brand new of 600 amperes. I also changed the points and installed a petronix ignitor module and 1.5 coil. Needle seems to be bouncing or fluttering a little bit on idle in the tachometer. How do i fix this?