the system for the tach use's the readings from the opti to run it. if theres no message from the opti then its not working right or there s a bad connection between there and the coil. if the tach works it does not mean the opit is good just tryin to get a little more info that would point to it

 

Hmmm! I thought I posted the fix that I found. I some how managed to break the hot wire going to the coil. The insulation of the wire was the only thing holding the connector to the wire. I purchased a new connector and pigtail from NAPA and soldered it in, plugged it in and fired that car up. Hasn't missed a lick since.

 

I'm taking it to a shop I purchased a new opti for 470 from gm gonna trace wires as well ill see how it goes