z28boysteve

iTrader: (9)

My tachometer works perfect when slightly revving motor or cruising around but when I race as soon as it get in the 6000 neighborhood, she bounces around like MAD! 3,000-7000, 1000, 7000 5000etc etc very rapidly. anyone have this problem? Should I just get an aftermarket one?

Nova5

No help here... interesting problem, i'd like to know the answer so ill post in here and sub it.

FIREHAWK #07

iTrader: (1)

maybe someone can loan you an aftermarket one for a day or two.... and see whats up... that is crazy.... never heard of that before....

z28boysteve

iTrader: (9)

ill most likely just buy an autometer with a shift light so I can be a little more consistant, anyway... but still curious

TwoFast4Lv

iTrader: (8)

I had a simular problem this weekend. opti started going soon after. I did clean the Opti harness and it helped but di not cure the issue. Seem maybe just the movment stired it up some

atljar

iTrader: (2)

I had a car I was working on do that too. The opti pigtail was rattling around causing the tach to jump all over. Check it over carefully.

A loose tach wire can do the same thing comming out of the PCM. Red connector, white wire, pin 13.

z28boysteve

iTrader: (9)

Thanks guys ill make sure to check those possibilities out, ill prolly still get an aftermarket tach just for the shift light (I have manual valve body) but Id still like the stock one to work right!