The distributor cap and rotor on a Nissan Sentra control the ignition and sequence of spark for the engine's spark plugs. As the rotor spins inside the cap, the rotor touches each spark terminal in sequence. As the metal terminals connect, an electric current is sent through the cap terminal points to the connecting spark plug wires. The spark plug wires transfer the electricity to the to the spark plug where ignition of the fuel occurs. As the rotor wears down, the transmission of the electricity and timing of the spark can degrade.
Locate the distributor cap by following the spark plug wires to the point of connection.
Note the location of the spark plug wire connections. Keep the spark plug connections on the distributor cap. Noting the spark plug wire location ensures you replace them correctly. You will move the plug wires to the new cap when you're ready to do the final installation step.
Loosen the distributor cap from the housing by unscrewing the retaining screws holding the cap in place. Remove the distributor cap and set aside.
Loosen the set-screw, which is located in the side of the rotor. The rotor is the device which turns inside the distributor cap housing. Note the location of the old rotor before removing the screw, and replace the new rotor in the same position. Loosen the screw. Pull the rotor straight off the distributor post.
Install the new rotor. Tighten the screw to secure the rotor in place.
Set the new distributor cap near the old distributor cap and align them so their positions match. Move the spark plug wires, one at a time, from the old cap to the same positions on the new cap. Install the new distributor cap over the rotor and replace the two retaining screws.
Start your vehicle to confirm correct installation.
