i have a 95 caprice with the lt1 i checked for spark and im getting it but it looks week on some cylenders so i replaced the cap and rotor and im still getting the same problem... i pulled the fuel rail to check for injector pulse and they are pulsing. replaced icm and checked coil. im wondering if its possible that the optical sensor maybe bad. is there something else i should check?

 

fuel pressure.

 

yes there is fuel pressure 47lbs