hello everbody I have owned my early 260 z for 29 years fully restored.1983 zx motor and 1971 4 bolt round tops su carbs. I just joint this site, looks like a good forum my name is kully. I been looking for some help ,I installed a new 1979 zx dissy and can not get my tach working. tried some resistors of different values but tach seems to jump around at idle and at high rpms works ok but when I slow down it jumps around. can anybody help with a solution thank you kully

on a 240Z, you bypass the Ballast resistor. But if the tach is jumping around on a 240Z after that process, the tach is probably bad.

If you have the 3 pole ballast resistor, run a jumper on the end bolts, not the middle one. if the tach still jumps around, you might need another one.

FWIW,

Dave.

If you are

Edited December 30, 200816 yr by beandip

If you are using the '79zx dist with the '79 coil you do not use the ballast resister . this is the set up I am running also.

I am not running the ballast resistor I took the blue wire from the tack and hooked it up to the neg. side of the coil and tried some resistors . tach works fine with orignal 74 daul pickup dissy got to be some way to get the tach working