Erratic LSE engine rpm

[alcladrv]

I've been experiencing an erratic engine rpm indication on my Plasma II+ system. It drives the top/right plugs and a Slick 4371 drives the bottom/left plugs on the O-360 in my -7A. The LSE tach is displayed on my G3X and the magneto rpm displays on a GRT EIS-4000 that I left some items connected to after I shifted most to the G3X.

The magneto tach is steady as a rock and LSE tach on the G3X jumps all over the place. The LSE tach was similarly steady until about 6 months ago.

I've cleaned and reconnected the 15 pin connector to the LSE several times. Has anyone else experienced similar issues that can offer some suggestions on how to correct it? Time in service is about 1300 hrs. over the past 12 years.

Thanks, Mike

[lr172]

any chance you did an upgrade or reset the G3X when it happened. The pulses from the mag and EI are usually different. Don't know the Garmin, but wonder if it has a configuration setting for mag vs tach output. If not, I would check the wire from the LSE to G3X for a loose connection.

Larry

[alcladrv]

Followup.

Found a bad solder joint for Tach wire inside the Lightspeed Input connector. After resoldering it, the indication looks to be normal now.