Coolant killed an injector?

1990 xj, 4x4 4.0
SO basically, i had a waterpump shaft go out-of-true, and it ate a belt, so i replaced the waterpump, and installed a fill thingy on the upper coolant hose to bleed my renix CLOSED coolant system.... easy enough....
But then when i started it, it was running on 5 cylenders, it was physically running rough, and no power.... i diagnosed it as being down a cylender, and began testing spark, it had spark to all 6.

so, i checked fuel, by unplugging each injectors electrical connection, one at a time, and listening for the engine to slow down, indicating the unplug
ed injector was not working prior to being unplugged...found injecter numero dos was not firing, yet had roughly 1.5 - 2volts supplied to it.

so, a junkyard trip later, all is honkey dorey after replacing the #2 injector...

is this normal? ive killed a lot of stuff steam cleaning/degreesing my engine, but never even contemplated covering the injectors...

does liquid kill injectors often? its hard to imagine this being a coincidence....

More then likely it was a corroded connector or that one injector had started to corrode internally. More of a coincidence that it happened during the time of your water pump.

Two volts is not enough to run a fuel injector.

Theoretically, you could short out the injector drivers by shorting the two together-possibly with water.