Errors in Tacho System (rpm measuring system) cause Engine revolution to fluctuate (hunting). Why does Engine Tacho System may fail?
RPM measuring failures may be related to:
- Sensors misaligned
- Sensors dirty. Grease and oil accumulated on sensors contain metal particles which disturb signal shape
- Clearance from the flywheel is too big
- Short circuit of the sensor wiring to the Engine
- Electrical errors in the Tacho (RPM pickup) system
