Tacho probs

[tuttle]

The tacho/rev meter in the R33 is only spradically working.On start up it flickers between 500-1000rpm,if throttle is gently applied it drops off to nothing & dies,occasionally returning at the 500-1000 reading for a few mins.The movement is flickery,like the old analogue cable type,when the cable was trapped/kinked.
I can still get a good (realtime)digital revs reading from the ECU map screen,so logically the sensor must still be OK.Also traced & inspected all the relevant under-bonnet wiring/connections & they appear OK.
So not a dramatic prob,just want to get it fixed.

Before I pull out the dashboard,fiddly(to check the dials & assoc wiring)anyone got any clever/interesting ideas?Dash clocks ought to be a fairly generic type bit of kit,I would have thought.

[iaint]

Same thing happend on my FD - the tacho occasionally blips 500 or so (no real change in revs) and sometimes sits at @2k above actual. Worse when it's cold out and about and is attributes to bad solder joints on the main dash pcb...

likely to be a signal/voltage related issue...