90 5.7l won’t idle

[90c15005.7]

Hi all,
I am having trouble with my pickup idling at all hardly. I have replaced cap, rotor, plugs, wires, ICM, pickup coil, coil, and IAC. So far I have either been able to get it to idle perfectly for no more than 2 seconds. And ran ok with throttle. Changed up timing with distributor as I took it out to replace pickup coil, and now I have a super super low idle for about 3-5 seconds and no throttle response. I am currently getting code 12, and this is after the diagnostics code flashy flashy. I have also rebuilt the throttle body. Any ideas on how to make this thing run again? New ECM? Thanks