[1968FastbackN20]

Sorry for the late reply but I have no computer at work.

If the FPSS switch is wired correctly it won't fire with the motor not running. I would jumper the FPSS and see if everything else works. DO NOT SHOOT THE NITROUS INTO YOUR MOTOR, USE A BUCKET!

If that test passes then I would look at what fuel pressure the motor has at WOT. (without nitrous) if it is adequate then I would take a guage and hook it up to my nitrous system (fuel side) and set the pressure on the FPSS. Your kit instructions will tell you what fuel pressure you need to run at the solenoid.

SIDE NOTE FOR NITROUS USERS:

It would be a very good investment for any of you to invest in a "Master Flow Check Kit" it is a simple kit designed to set flowing fuel pressures through the fuel jet.