Injector spray pattern

[Erik Addy]

I am aware of the need to change CIS injectors based on deteriorating
spray pattern, but is this also a problem with Motronic electronic
injectors?
3 or 4 of the injectors in my 90q20v (7A engine with Hitachi injectors)
have already been replaced, although one with a used injector acording
to the previous owners records.  Currently, all injectors test out fine
using a multimeter, but I cant help but think that an injector with
170,000 miles probably doesn't have the greatest pattern, even if it is
fine electrically.  Any experience here?  How could I test them
(meaning, after removal, how do you get them to spray?).

Thanks,
Erik