Did you hook up your rpm signal to the ecu rpm signal on the ecu harness? Mine is loosing rpm signal after 5800 rpm . I even solder the wire to the ecu wire and same results. I wonder if it has something to do with having an AFC and Shift light hooked up to the same wire. I hooked up an autometer tach to the same wire and it works fine all the way to red line. I have to calibrate the rpm /3 to get it read correctly on the interface.
