Update. Well I changed out five of the 6 injectors, and the stumbling start is basically the same. Although the car had been running plenty smooth, it runs even smoother now. The last injector is the one right by the cold start valve so I'll change it with the cold start valve. There are also some air hoses there and I just know they'll break if disturbed. I also tried a new fuel pump relay, which powers the cold start valve but again no change to the start. So that leaves me with the cold start valve as the last item to change. I'll throw in the towel after that.

glenmore
1991 300CE
2000 C280
1990 LS400