When you take loose the wire from coil pack on number 2 it makes no change in the way motor runs

I have a 1996 Infiniti i-30. I had sold this car and gotten it back after new owner tried cleaning the injectors and decided not to purchase it. When sting to put the car back together I realized he had discarded the plastic tips on the injectors.I engineered my own witch does he same thing other than the mist quality. I believe this will work a least not cause the problem with the misfire on number two. Am I wrong in this? I will replace if needed after I get car running. Got a new injector o-ring kit and installed it witch go he car running but not well. Following he codes I replaced coil pack then cam sensor making no difference. Ive been told to check for vacuum leak in that area but have not found any obvious leaks. You can take the wire from coil pack on number 2 it makes no change in the way motor runs. Am I missing something And what vacuum line specifically should I look for. What about the plastic tips am I wrong about them causing he misfire. One other thing last time I worked on car if you gave it any gas it seemed to flood. So what do you think?