If one cylinder is not working (either because of fuel or spark for
example) you could run the car and pull the spark plug wires for each
cylinder one at a time - when you unplug the bad cylinder - the engine
should not run any differently. Once you have figured out which
cylinder is not firing, you can diagnose further.

As an aside, you can get a piece of rubber tubing or a long screwdriver
and use it as a stethescope to listen to each injector - you should
hear distinct clicking for each injector pulse... see if find a dead
injector. You can confirm that cylinder is indeed dead with the method
I described above.

Cheers
Nirav
96 Max GLE, 118k