Are you saying that if you pump the marker then pull the trigger nothing happens? If this is the case the hammer is not catching the sear at the back of the pump stroke. Assuming the cocking rod is screwed in tight there are three possible explanations:
1) you're not pulling the pump far enough back.
2) the thing that you turn to raise the velocity at the back of the lower tube is too far in preventing you from being able to cock it back far enough to engage the sear. Try backing it all the way out and see if it will cock now. If not go to stage three.
3) the bit that sticks out of the bottom of the hammer isn't far enough out to catch the sear, take out your bolt and there should be a hole in the top if the marker that you can stick an Allen key through, turn it clockwise a turn or so and try pulling the back block to see if it will catch now if not turn some more.
If none of the works take your trigger frame off and take picture of the top of your trigger frame looking down into it and one looking up into the bottom of the body and post them up.