JT8D-9A N1 readings
We are having problems with our N1 readings on our C-9B aircraft. There is a flucuation in indication sometimes. Others times it works perfect. We have replaced the N1 Tach-Generator and the cocpit display. After doing this it stillcontinues to flucuate. We did a eng. run up and on eng. start N1 read 0 not dashes, so i know its getting a signal. As i ran the eng. up to 1.2 epr it began to flucuate and then at 1.2 returned to normal and continued to read normal for the rest of the turn. Any other ideas what to check for this problem...Thanks