At idle or below 15k its ok but once near 20k it drops back down to zero. I did pull it out recently while cleaning engine bay but I did grouped wires to correct terminal with tape. I tried another TACH but same issue. Ive scanned the forum and the wiring diagram for my 84 but haven't been able to track down problems, or confirm my wiring. I see from mirafiori's site about the cap installation and also a series resistor option from another forum, guess I have to try that. I'm trying to avoid replacing anything yet, new coil, module. Also before I check resistance on coil itself. See from my set up:

I have yellow and blk from module to neg side.
brown, pink,(red-module), (black-condensor) going to pos side.
Not sure were Yellow is going.
Does this seem ok?
Any insight is very appreciated.