try this,disconnect the coil.(you do not want the engine to start) pull number 4 plug( or the cylinder with no compression) put your finger over the plug hole.have some one turn the engine over.(or remote starter switch if you have one) see if you can feel suction or pressure in the hole. if no suction or pressure you have a broken connecting rod.if you do feel suction or pressure you have a valve problem.(stuck or burnt) you will need to pull off valve cover then rocker assembly tap the valves with mallet to see if they are stuck its hard to see if valve train is working correctly with everything running
