Step 7: Program activation switch.
Now that you have completed the wiring of your nitrous kit, the next step is to program the Activation Switch. To program the Activation Switch, turn the vehicle’s ignition on, but do not start the engine. Turn the nitrous arming switch to the "ON" position. Go to the Nitrous Management Unit (NMU) and locate the push-button switch. Depress, then release, the push- button switch. Observe the NMU’s Operation Light. At this point, it should be RED. This RED light informs you that the NMU’s Activation Switch is in learn mode. Return to the driver’s seat and depress the accelerator pedal to the floor, holding it there for ten seconds. Release the accelerator pedal and go back to the NMU and observe the Operation Light. At this point, the light should be flashing continuously from RED to GREEN to OFF. This is the NMU’s way of telling you that it has successfully learned the voltage curve of your engine’s throttle position sensor. Go back to the driver’s compartment and turn off the system’s arming switch, then turn it back on. Go back to the NMU and observe the Operation Light. It should be solid GREEN at this point. This informs you that the system is armed and ready to activate at wide-open throttle. Return to the driver’s seat and depress and release the accelerator pedal several times. You should hear the solenoids click each time you reach wide-open throttle. At this point, your Activation Switch is fully programmed and ready for use. If you ever transfer your nitrous system to another vehicle, perform this same procedure on the new vehicle to "relearn" the NMU’s Activation Switch.
Step 8: Install fuel delivery line.
The first step in installing the fuel delivery line is to determine where you would like to draw the fuel from. The ZEX™ nitrous kit comes with several fittings that will allow you to decide what the best solution is for your vehicle. If you would like to use the fuel tee fitting, ensure that the fuel line pressure has been relieved and then cut the rubber fuel line. Insert the barbed ends of the fuel tee into the rubber hose ends and secure with the provided hose clamps. Using an appropriate thread sealant, install the 90 deg. -4 AN fitting into the threaded hole. Another option is to remove the fuel rail and drill and tap it for the 90 deg. -4 AN fitting. Pick the spot you would like to drill and mark it. Using a 11/32 drill bit, drill the hole and then tap it with the supplied 1/8 NPT tap. Using an appropriate thread sealant, install the 90 deg. -4 AN fitting into the threaded hole. Before installing the fuel rail back on the engine, ensure that all metal shavings have been cleaned out. There are also certain vehicles that have a -4AN Schrader valve fitting, factory attached to the fuel rail. Once the valve core is unscrewed and removed, with the tool provided in the ZEX™ it, this factory fuel rail fitting makes for a very clean and easy hook-up for the nitrous system’s fuel supply hose. Finally, a 1/16 NPT to -4AN fitting is also included for easy connection on vehicles that contain fuel rails with a 1/16 NPT access port. Once the fuel fitting has been sorted out and installed, connect the -4AN, 36” hose assembly to the fuel fitting and the fuel inlet on the nitrous management unit. This completes the fuel connections for the ZEX™ Part #82021 nitrous system.
Step 9: Check fuel and nitrous pressure lines.
To ensure that the system is ready to be used, a final check of the system’s fuel and nitrous pressure lines must be done. With the engine running, check your fuel lines for any signs of leakage. Correct any fuel leaks before proceeding! Assuming the fuel lines check out, turn off your engine. Open the nitrous bottle valve. Listen carefully as your valve is opened. Inspect the nitrous pressure lines and fittings for leaks. Leaks in the nitrous supply line will be obvious because they will be covered in frost.
Step 10: Check fuel quality & ignition timing.
The last two things to check before enjoying your new ZEX™ nitrous system are the fuel quality and ignition timing. First, ensure that premium fuel (92 R/M octane or better) is in the fuel tank. Premium fuel will ensure maximum safety and detonation resistance for your engine. Second, make sure that your ignition timing is set correctly. All recommended ignition timing retard amounts, on the tune-up sheet, are calculated off of the base, stock ignition setting. It is important to set this with a timing gun before you use your nitrous system for the first time. Do not assume that it is set properly. If the ignition timing is not set correctly, severe engine damage may occur. ZEX™ does not recommend the use of aftermarket “tuning” chips with our nitrous systems. These chips tend to advance ignition timing and can cause engine damaging detonation when used in conjunction with nitrous injection systems.