Another issue with the 4G15 engine is that over time the distributor O-ring loses its flexibility and starts to leak. Read on for some pictures and notes on replacing this ring, the cap, and cap rotor.

• Rotor - $15
• Cap - $25
• O-Ring - $6, from the Mitsubishi dealer

The distributor is essentially a mechanically activated transformer that takes 12V from the battery and amplifies it to tens of thousands of volts. As the engine turns so does the distributor and rotor. At exactly the right time the rotor makes contact with the correct post on the distributor cap that corresponds to the cylinder that needs to be ignited. The high voltage gets discharges from the post across the spark wires to the spark plugs of each of cylinders 1-3-4-2, in that order. For the discharge to be complete the electrical properties of the rotor, cap, wires, plugs and ground points have to be as per the specifications.

To start with, make a note of each spark wire and what post on the distributor cap they connect to. Below I just disconnected the #1 wire.

After removing all wires, you can use some engine degreaser to break loose any dirt and grime. Unplug the distributor electrical harness. Unscrew the little connector on the distributor housing.

Depending on your tools and room around the distributor, remove the distributor as a unit or remove cap first to make it easier to reach the bolts fastening the distributor to the cylinder head. The cap is held in place by two small bolts. As you get to the end of this process hold the distributor with your hand to prevent it from falling.

To make reassembly easier make a note of the position of the distributor key and where the taperred end is. Also make a note of how the pin was coupled to its counterpart in the camshaft and where the "D" stamp is.