XDI Tach Signal

[bullethole]

I've installed an elecromotive crankfire wasted spark ignition, works great. However, when I tie my data acquisition system into the tach signal, the DA system will read a clean tach up to about 4000 RPM (above 3000 it jumps around, but will indicate a peak of about 4100 RMP). The stock tach reads perfectly. I'm wondering if anyone else has found issues with getting a clean tach signal to a secondary digital display.