i just installed a auto meter tach. i have a b16.
i have my shift lite set at 8000
when my needle goes up near 7,8 it jumps all the way to ten. and its not a smooth jumps it skips.
it does not do that on my stock tach.
could it be from a shitty ground for my tach?
or the fact that my distributor is acting up.(ignitor)
my stock tach gets jumpy some times at high rpm but not like the autometer.
it actually skip from 7 ,8k to like 10000 sometimes 11000 even though the motor is not reving that high. this cause my shift light to activate to soon.

 

ne1

 

distributor I would have to say. Try a new one or some one elses. Mine did the same thing. a new one cured the problem and made it run better.