Erratic Tacho reading

[CMF_speedline]

Ive just installed a set of super S guages into my 1.0 1997 shape micra, ive run a wire from the blue wire on the top of the distributer/coil to the blue wire behind the guages, the rev counter now works but is giving erratic readings , jumping from 1000 to 2000 then back to 1000 then 2500 , the engine speed is staying at idle speed, is there anything i can try to resolve this problem.
thanks in advance for any help,

BTW great forum

cheers

 

[CMF_frank2]

speedline

i wired a standalone rev counter to the same blue wire and it worked fine, so it could be the gauges end (maybe different plugs or an earth problem ?)
the haynes says the tacho is fed from the ecu (blue/black wire)

frank

 

[CMF_SSUK]

I just plugged the super s gauges into my 1.0, there was no need to connect a wire from the distributor. There are subtle differences in wiring looms between models it seems.

I would wire from the ecu rather than the engine bay, as there's less chance of interference.