I think I'm having the same problem. It's been sitting about a year. We just rebuilt the motor, so compression isn't an issue with mine. We pulled the rail & injectors, and the coil wires, then cranked. Sure enough I have 3 injectors not firing. #'s 2,4, & 3 have no spray. I haven't been able to get it to run long enough to idle yet. It's been firing everyone once in a while. I like the little injector cleaner video, I may try that. I have a guy that does em' for $20 each, but I'm broke.

 

Since it's not your primary means of transportation you may just want to pull the injectors off and soak them over night in some cleaner. Just remove the O-rings if you do this so the cleaner doesn't dry them out. Or replace the O-rings all together.