My AFS 2500 began life as an AFS 2002. After upgrades. it is now an AFS 2500. Recently my tach indication began jumping up and down about 20 to 30 RPM. I checked the connections under the cowl. They are all very tight. I checked the connectors at the module and they are tight. It is in a Van's RV-7A with about 1000 hours on it. It has one impulse mag with the hall effect sensor in it and a Light Speed electronic ignition. Could the sensor have failed?