Don't over lube
I only oil very little and do not take my E-Mag to bits.
Switch the air supply on and fire it in a bucket of water to clear any dirt. If you still get problems, contact AGD, they are pretty good about helping.
Sounds like an old on/off pin seating problem on the Automag but I'm not sure if E-Mags work in the same way as I haven't disassembled mine yet. Leave that to AGD unless you want to risk running up more bills for repairs if you don't know what you are doing.