"The injector trimming is usually not used to trim injector flow difference (i would advise to have these cleaned and matched) but rather compensate for bad (or good) manifold flow on specific cylinders etc."
Injector flow, intake or outtake flow same battle!
One may say that it is useless to have the injectors matched because the air flow for each cylinder is probably different so that the injectors need to be unmatched ;-)
With efficient statistics analysis done on the lambda variations which follows some well crafted individual injector and spark perturbations, one might get some characteristics for the cylinder (air stream, fuel stream, burning). Well not that easy. Any SAE paper on this?
Philippe