I have replaced plugs, cap, rotor, wires and coil and I still have a dead plug. Any ideas on what to check?
It is possible to get a defective plug, rare but possible. Replace the dead plug with a known good plug. If the good plug still doesn’t fire check the compression in the cylinder. Poor compression will make the cylinder “dead” even if the plug is firing.
If your motor has a fuel injector for each cylinder, the fuel injector for the dead cylinder might not be injecting any, or not enough fuel. If you have good compression, then the fuel injector might be the culprit.
There is no spark from the plug and I have switched plugs with a good plug.
You’re saying you have the plug wire disconnected from the motor, and you’re checking it by turning the engine over, and you don’t get spark? Did you check this plug the same way on a different cylinder?
Check the plug wires again. If the other 7 are sparking, and 1’s dead…it’s either the plug, wire, or the cap got damaged somehow.