Ford Repair: 03 TAURUS DEAD CYLINDERS, oil filler cap, harmonic balancer

Question
03 taurus 30ohv 1,2 and 5 cylinders are dead .I have spark, injector pulse and compression. I switched injectors, miss is still there. Vaccun leak at plenum ? 155000 miles started doing on the interstate

Answer
possibly broke valve spring/springs-vac leak at plenum unlikely unless severe and you should be able to hear that-internal vac leaks possibly pull off oil filler cap to check for vacuum at valve cover-you can have it smoke tested for leaks-broke or damaged crank sensor ring on harmonic balancer.