I recently purchased a 1995 sentra gxe for my son i have good fire at the plugs but it wont start ,while checking the fuel side i removed the fuel hose at the filter output and installed a pressure guage and the motor started and ran for a second or so then cut off however it wont start after reinstalling the hose i cant figure this one out on my own ??????

go rent a fuel presser gauge. check the fuel pump. the lines if you go threw all that. the check the fuel rail and maybe the injectiors. good luck.