To pressurize the system and check for fuel leaks… do not start engine, but let the ECM power the fuel pump for 5 seconds when energized. Have a Fire extinguisher available for use at all times.
The Fuel Injector is installed and torqued during the manufacturing process and should not be replaced/tightened under normal circumstances , but if replacement is directed a strict replacement torquing is required. If the injector is over-torqued, it will cause the injector to malfunction.
UPDATE: Kits manufactured before June 2019, can be upgraded using 1/4″ steel tubing cut to .90″ inch and placed over the hold down screws as sleeves. This will allow torquing the hex head screw without over tightening causing injector seal leakage.
The injector may also leak a small amount of fuel initially, but then the o-ring will seal the leak shortly after the injector seal swells from contact with gasoline. A small amount is a drop or 2, not a spray or an amount that would cause a fire risk. If the injector seal continues to leak fuel, then a replacement seal must be installed and injector housing checked before re-installation.