Nope still screwed up, my 2 solutions I am presented with are ecm reset or my voltage is too low

 

FWIW, my truck exhibits the same after my battery runs down (when the dang kids leave the dome light on in the back without me noticing). But after a good long ride (battery charge) and a re-start, all is fine.
So there may be something to the voltage theory. Is the battery well grounded to the frame? That connection is notorious for corrosion and poor grounding.

 

I think so, but definitely worth a second look

 

Definitely worth a look as I was dealing with an irritating tach bounce and sorted it after I cleaned my frame ground that was caked in mud and gunk/slight corrosion. However mind was just the gauge and not actual rev spikes

 

Clean, solid grounds. But then again, didn't experience the problem today. Maybe tomorrow, maybe next month before it happens again, who knows