Thanks for the results, I have a reading of 1.8 ohms on the 2k scale, 1.8 ohms on the 20k scale. Bumping the engine around does not produce a different reading as I thought it would. I have ordered a new sensor (aka Engine RPM Sensor).
Sunday, after church the tach started working!!! Looking at the sensor wiring, it's apparent there is a break inside the sensor itself, affected by outside conditions (heat, cold, wind speed). Alan