1990 tbi 360

On my d250, I have done a full tune up over time since i git it a few months ago. traded an acura for it to work if and make a few extra bucks. tune up includes: plugs , wires, cap, rotor, fuel /air filter, PVC valve, vacuum lines. The truck however is still running rich. I'm wondering what else I may be overlooking aside from timing? Someone once mentioned to me to tune the regulator. not sure how to do that?

I included a wiring diag of the engine for those unfamiliar with this setup. Not sure if it will do any good or not lol.