Jpi-830 rpm jumpy

[M016576]

Gents- I recently upgraded my JPI EDM 830 software to 3.38 and have noticed that my RPM is jumping back about 60-75 rpm every 5 minutes or so for a split second. Has anyone seen this? My mechanical tach doesn't budge, but the rpm jump is so fast the mech. Tach might not be picking it up. Both mags are solid during checks, so I don't think it's a mag problem. Loose ground or loose connection to the hall sensor maybe? What says the crowd?

[Jeff_S]

I have a Horizon digital tach and it occasionally jumps around like that. I've never worried about it, as numerous things can affect it but none seem consistent so I don't see it as a problem. The problem with digital tachs is that you get zeroed in on trying for perfection because, well, you can! But RPM jumps around in a band of 20-50 quite frequently so you just have to pick a general spot and leave it there.