Tach Weirdness + SI Board Interchangeability

[krazy]

Hey all,

My tachometer occasionally acts weird. It'll sometimes only move around in coarse increments. i.e. It'll jump from 0 to 1k to 3k and sit at each as RPMs vary between them (as opposed to smoothly moving through the range). Most of the time it works perfectly, but this will happen a few times a month.

I've smacked the dash plenty and that doesn't ever seem to fix it.

So I'm beginning suspect it has to do with my SI board.

It's a VDO cluster. I have a parts car with MotoMeter cluster. Any idea if I could swap the SI boards between the two? What about the entire cluster?

[earthwormjim]

Brand is not the limitation with SI boards, it's model year. If you have an early model cluster, you need an early model SI board. Late model cluster, late model SI board.

http://bavrest.com/technical-articles/bmw-e30-si-board