91 camaro 3.1 Ecu switches from open to closed loop after warm up causing flooding and stalling o2s always rich wno ses light and the plugs are pure black after 50 miles you have replaced all injecter?
it is probably out of time? i own o 91 camaro 3.1 myself and
pulled injectors, and plugs where the same. maby one of the
injectors wasnt in place when runing? you cam might have a flatend
lobe as well so it could be throuwing the valvs in dif. rotations.
I would also check you distributor maby a spring broke loose.