doesnt sounds anything like a solenoid problem to me.
sounds more like a valve leak......turn the gas on and while its leaking put your finger into the breech if you feel the air hitting your finger im correct. it will possibly make a comedy farting noide when you do it
(oh and dont pull the trigger with a finger in there! take the bolt out!)
this can usually be fixed by shooting the gun a couple hundred shots to bed in the face of the valve, if that doesnt help drop firstname.lastname@example.org
a quick email or a phone call and he will be able to offer more help than me