tach installation '99 cavi

hey i have a 99 cavi and its my racecar. its a 5-speed and i need to get my tach in it..but i've tried several wires and none of them work very well. i got it to kind of work on one wire but it was reading backwards (it would be idling at like 3500 and then you give it some gas and it goes to 0) any help would be awesome cuz im ready to throw the damn thing away.
thanks!!

to make things much much easier you will need a tach adapter, that adapter has 3-4 wires, mine has 3, what you do is take 2 of the wires (you will know which 2) and splice into 2 ignition related wires right under your intake, the other wire is the one you connect to your tach, for the "signal"

your tach has a switch for 4, 6, and 8 cylinders, if your tach also has a setting for 2 cylinders, theres another way to do it, if your tach cant be set to 2 cylinders, the tach adapter is the only way

so if i were to get like a sunpro tach with the option of 2 cylinders..it would work? or should i just get a new tach and an adaptor too?

thanks for your help! :]

i dont exactly remember how to do with with a tach set to 2 cylinders, but i do remember it IS possible, however i do know that doing it with an adapter is really quite easy

Even in a sticky with big bold letters... sheesh..

http://www.automotiveforums.com/vbulletin/showthread.php?t=375752

then set the tach to a 4cyl setting according to tach instructions.