so here is the problem.... 86.5 supra, na, 5 speed, kinda stock. i pulled the gauge cluster out today to calibrate the speedo. had it all apart to change the needles on the rest of the gauges to some cool ones i had laying around. never touched the tach except to pull the needle off and put another one back on. put it all back together, put it in the car, and now the tach, at idle, reads about 200rpm, and when i rev it, at about 4k, it will jump all the way past 8k. it does not ever read what the motor is actually doing. i have two other tachs, but they are turbo tachs, so they are of no use to me. i have a good tach signal at the back of the tach. any ideas as to where to go with this? any help would be great. thanks