Tach problems

[t_ruffcorn]

Hello! Finally got around to putting my tach in got everything installed and tested everything before I buttoned it all up and It will only read on the tach at about 2500 rpm and up and, Isspro 8503 tach and isspro harness also have a fluidampr on the truck. Anyone have any ideas?

[thrashingcows]

Could be a bad CPS, or mis-adjusted one? The signal to the tach comes off the CPS....so I would think this might be your issue?

[dr_funk]

Is the gap set correctly on the crank sensor?

[dr_funk]

I have an isspro on mine and it drops out when the truck idles rough in the cold. I believe its the vibration that throws off the readings. Revving it up smooths it out and it reads properly.

I forget what the gap is supposed to be on that magnetic sensor, but its very slim.

[dr_funk]

Did you install the magnets on the outermost edge of the fluidampr, or down in the gaps?