How to replace the distributor cap on a 1970 Plymouth Hemi 'Cuda?

The distributor cap in a 1970 Plymouth Hemi 'Cuda is a critical component that distributes high voltage from the ignition coil to the spark plugs in the correct firing order. Over time, the cap can wear out, leading to misfires, rough idling, or even a no-start condition. If you're experiencing these symptoms, it might be time to replace the distributor cap. Here is how to solve this issue.

Step 1: Safety First

Before starting any work under the hood, ensure the vehicle is parked on a flat surface and the engine is turned off and cooled down. Disconnect the negative battery terminal to prevent accidental electrical shorts or shocks.

Step 2: Locate the Distributor Cap

Open the hood of your 'Cuda and find the distributor cap. It is usually located at the rear of the engine bay, towards the driver's side. The cap is a rounded plastic cover with several thick wires attached to it, known as spark plug wires.

Step 3: Remove the Spark Plug Wires

Carefully note or mark the position of each spark plug wire. It's crucial to reinstall them in the same order to maintain the engine's firing order. Using a masking tape and a marker can help. Gently twist and pull each wire off the distributor cap terminals.

Step 4: Unscrew the Distributor Cap

The distributor cap is typically held in place by two screws or clips. Using an appropriate screwdriver, unscrew these fasteners and set them aside. Lift the cap off the distributor carefully.

Step 5: Inspect the Rotor

With the cap removed, you'll see the rotor inside. It's a good practice to inspect the rotor for wear and tear while you have easy access. If it looks worn out or corroded, consider replacing it as well.

Step 6: Install the New Distributor Cap

Align the new distributor cap over the distributor, ensuring it sits flush and the screw holes align correctly. Secure it in place by tightening the screws or reattaching the clips you previously removed.

Step 7: Reattach the Spark Plug Wires

Refer to the markings you made earlier and reattach each spark plug wire to the corresponding terminal on the new distributor cap. Push each wire firmly to ensure a good connection.

Step 8: Reconnect the Battery

Reconnect the negative battery terminal.

Step 9: Test the Engine

Start your 'Cuda to ensure the engine runs smoothly and that there are no misfires or rough idling. If everything is running correctly, you have successfully replaced the distributor cap.

By following these steps, you can effectively replace the distributor cap on your 1970 Plymouth Hemi 'Cuda, restoring proper engine performance.