Check your fuel pressure. Not sure what it should be for your MY and fuel setup. Considering the list of fuel parts that you have replaced, I would guess that the car had sat for a long period of time at one or more points in its life. It's possible that your FPR (fuel pressure regulator) and/or FPD (fuel pressure dampners) have seized diaphragms as I discovered on a poor running 928 this past weekend. Varnished fuel will do this. This will cause a lean or rich mixture at virtually any throttle position depending on what position the diaphragms seize. The diaphragms are also known to rupture. You can check the vac lines for the presence of fuel to confirm this.
I would think that your FPR and FPDs were in that bad of shape that your fuel distributor would be as well.
I'm not the most CIS savvy person out there.
Just a tip.