tacho jumping

[SoarerTT]

hey guys i bought an autometer tacho the other day and i hooked it up to the coil but as soon as it hits about 5000 rpm it starts jumping so i took it to guage works and the said i need a diode so i bought one but it didnt help so i then got the tacho tested and its fine.

then the guy at guage works told me it might be my coil so i went and saw a mechanic and he told me that those sort of tacho need more power so i might need a new coil..

so i then a place and asked about getting a new coil and told him what was wrong and he told me that was wrong so he is now calling autometer tomorrow for me.

i was just wondering if anyone has any idea wat could be going wrong!!!

cheers Ryan

[Adam_Cressi]

the coil u have emits a pulse that ur tacho cannot read ??? :S

[Cuzzo]

Wat car? wat engine? any mods?

[ndgcpr]

maybe you need a tacho boster, some "old" type use the voltage spike from a coil. Most soarers run a 5V tacho output, although i would think it would not work at all. I got this circuit from someone, i can't remember who though. maybe willbo