Ok. I tried searching for this before posting a new topic, but this is kinda unique. My problem is this:

When I gas up my PC (20oz. CO2), there are no leaks and everything seems to be ok. I start shooting(dry firing) and the first couple shots work and sound as advertised. After that, however, it starts to lose pressure as if it were running out of CO2. The shots get weaker and weaker until about the 6th or 7th shot when it quits and does not recock. If I recock it, it does the same thing, shoots well for about 2 shots, then starts to die and evetually dies again. First off, I know 100% that there is CO2 in the tank. Second, I have completely taken it abart and cleaned, lubed, and replaced O-rings. Nothing is working.

Any ideas?

Thanks for any help!

Don't hook CO2 to your computer!
Sorry, couldn't resist.

Does the pro carbine use valve bolts like the 98C? That could be allowing the valve to move slightly, which is a common problem among 98's that gives a similar effect. You have dropped oil directly into the valve, right? Also make sure the valve pin isn't deformed (if not properly oiled, the pin will deform and become compressed, causing the pin to actually shorten in length but increase in diameter). Check the feed lines, clean those out and make sure nothing's blocking that (old teflon tape, etc.). And when you say you've taken it apart, does that include taking the valve apart?

If your tank is not screwed in all the way and/or just idleing on the ASA pin, the slightest movement will close the pin, or open it. So screw in your tank all the way if not done already.

Or the pressure in the ASA pushing in every direction including the tank away from the ASA, will push it a tiny bit and disengauge the pin. So that when the pressure is low or out it will be reengauged.

A worn ASA can cause this. So try replacing that (Call Tippmann, ask for part #CA-08 which is $12.)