Get yourself a 50 dollar LCR meter from jaycar. Its an inductance/capacitance/resistance meter. All you should care about is the inductance.
with my 4 injectors out, but the coil still attached to the injector body ( its a real pain unclicking those things too) i measure the inductance and resistance.
3 measured 4.4 ohms, one read 4.3. not a big difference.
now.. turn it to inductance.
my values where
7.3mh
6.9mh
6.8mh
3.2mh --- this is the one that also measured low on resistance.
Thanks to a forum member who sent me a spare solenoid, i replaced that coil, and it measured good again, 7.1mh.
Now, measuring these figures will be different through the loom, however, its the odd one out you are looking for.
Just thought i would share this just in case someone finds its useful and needs to work out of an injector could be wonking out.