My question is. What would cause my Q-Jet to suck exsessive air at approx 2000rpm. I mean some pretty loud hissing going on. Also my mpg has gotten a lot worse as well. What could be wrong? I rebuilt her about three months ago,and since then. The only things I've done under the hood is a Carter Street and Strip fuel pump, Accel Super coil,8mm wires, new spark plugs, And a Nitrous system.

Any suggestions?

TTT

Check for any vacuum leaks. The carb gasket could be the problem. Check all that vac. lines too.