Guide on how to change an ignition control unit yourself.
Estimated time: 1-2 hours Difficulty: Medium
The ignition control unit triggers the coils to fire through the input from sensors feeding the Powertrain Control Module or PCM. The PCM is a circuit board computer encased in a heavy duty covering. The covering protects the board from extreme fluctuation of temperature in the engine.
Begin by disconnecting the negative terminal on the battery. You should always do this when changing any electrical parts. Undo the nut holding it in place and remove the negative connection. This protects you and any electrical parts when working with electrical parts on the vehicle.
Remove the connection from the distributor cap to the coil and then unbolt the two bolts holding the distributor cap in place. When the two bolts are removed, pull the distributor cap off and move it out the way.
Remember which way the rotor is facing when you take the distributor out, so that you can put it back the right way when done.
Remove any wires and disconnect the electrical connections to the distributor, remembering which wire went where. There are two bolts holding the distributor in place, disconnect these bolts and pull the distributor out.
This now reveals the ignition control unit and coils. Remove the connector to the coil by unclicking it. When this is disconnected, there are bolts holding the control unit in place, remove these bolts to remove this part from the vehicle.
The coils are held onto the control unit by clips, so unclip these and pull them out to separate the coils from the control unit.
Fitting an ignition control unit
Take your new control unit and connect the coils back in place. Bolt these parts back to the engine and reconnect the connector, clicking it back in place.
Put the distributor back by bolting it back to the engine, remembering to have the rotor facing the right way. Put the wires back in the right place and reconnect the electrical connections.
Put the distributor cap back on and bolt the two bolts in place, ensuring all bolts are fitted tightly. Connect the connection from the distributor cap to the coil. Re-connect the battery by re-connecting the negative terminal.
Test the part is working by turning the key on the ignition, and this completes the installation.