Have just been for a blat and think the vac pipe was a red herring as far as the tacho goes. The car has what i assume is Corrado clocks in it. 160mph speedo, twin LCD screens and a row of lit warning icons at the bottom. On the drive the rev counter fired in to life, erratically, mostly jumping all over the place. The oil icon also stopped flashing then started etc. Dashlight Disco! Waheyy. I suspect an earth or voltage regulator problem, does anyone have any other thoughts? Cheers.