FJO cutting in and out ???
are you sure its cutting in and out or is it a nitrous flow problem..maybe an ignition issue. set up the box so its just an on off switch (non progressive) and see if it goes away. Maybe wire in a test light so you can see when the noids are getting power. If its getting power and still surging...check the other things. You need to narrow down the search before you look back at the FJO.
Did you do the WOT test on the FJO? If you have the setpoint too close to the actual WOT, it can come in and out. You should be able to see it by watching the green LED that you use to do the test. Go to WOT several times with the car off but n2o armed - does the LED light properly every time? You may have to put a few more turns on the little set screw.
