Okay,I have 2007 maxima 3.6 .okay,so I replaced the timing chains,the car started and was running fine,I was looking over the wires and noticed a injector wire loose , so I went to push it in better and the plastic around the plug just broke like glass,this caused the wires to touch ,it made a loud pop and cut off.i haven't been able to get it to fire since.ive checked fuses relays I just don't know if there is something with these cars I don't know,besides the security system may be causing it.