my 94 3.4 suddenly has a major misfire. mostly under load. have replaced plugs,wires, coils and ignition module. could the pcm be bad or the crank sensor. when i do a spart test # 1 cyl shuts the engine down and will not restart until wire is hooked back up. thanks for the help

 

Misfire is usually caused by ignition problems, fuel delivery problems, or a mechanical problem. Since you shotgunned the ignition system to no avail, you may want to check the fuel system. Look for low fuel pressure, or one or more injectors not working properly.