I already put some grease on it, so I cleaned the diaphram and stretched out the spring so more pressure is pushing up on the phram and now it works like a charm! Thanks for your help!

The spring is still on and I tried stretching it out so it pushes more on the phram, but no dice. My first gun, BTW.

EDIT: I'm out for the night, i'll check back tomorrow

I created a pneumatic spudgun with a 3/4 in. LawnGenie sprinkler valve on it (with guide rod.) Because of the guide rod, I inserted the blowgun beside the guide rod, which was on the edge of the innermost hole. My gun worked perfectly until recently, shooting the handle of a shovel through 1 in wood...