Nitrous problems HELP!!!!

[Blaster]

I solved the problem, I don't know how or why but I set my MSD box to 0 and 0 on the RPM limiter (defaults the box to 12 500rpm) and my popping went away!!!! My buddy recommended trying it because he said I was probably loading up on the juice but not when running N/A hence no popping. I had my tuner get rid of the of the factory rev-limiter with a reburn of my chip because I knew I wanted the MSD to cut the RPM's by reducing spark (not fuel like the factory one). I had the box set at 6500rpms before. Any ideas on why this may have been happening??? Why would it have started popping at 4000-6000rpm when the limiter was at 6500???? Anyhow the car pulls like a SOB now. I just wish there was a way to make my purge solenoid stop leaking (Nitrous works, leaked from new!!!!) Can I tighten something on it???