I resurrected a set of CA18DET injectors recently for ZERO cost.
I carefully pushed the valve in at the end of the pintel cap as all four were initially stuck closed.
Got them freed up OK then I put them into my handy little Ultrasonic cleaning tub for a series of 100 sec. treatments.
Didn't get any crud out of them so I connected a 9V dry cell across the terminals [CLICK] and blew through the fuel hose.
VIOLA!
Dark yellow crud was vomited forth
Soaked them in paint thinners for a while and redid the battery and blow method.
So, just try a little mechanical coaxing, a little voltage, a little air pressure and some carb. cleaner
What have you got to lose