Here's a breakdown of what's involved in replacing the distributor on a '89 Mustang 302 HO:
1. Preparation:
* Safety First: Disconnect the negative battery cable. This prevents accidental shorts and protects your electronics.
* Gather Tools: You'll need a socket set (including a 1/2" drive for the distributor hold-down bolt), a wrench, pliers, a screwdriver (possibly Phillips and flathead), and potentially a distributor alignment tool (highly recommended). A timing light is helpful for resetting the timing after installation.
* Consult a Repair Manual: A Haynes or Chilton manual for your specific vehicle is invaluable. It will have detailed diagrams and instructions, including torque specifications.
2. Accessing the Distributor:
* Remove the Air Cleaner Assembly: This provides better access to the distributor.
* Locate the Distributor: It's usually located on the passenger side of the engine, near the firewall.
* Disconnect Components: Disconnect the spark plug wires, carefully noting their order. A good way to track this is to photograph it before removal, or number the wires and the corresponding spark plug locations. Disconnect the ignition coil wire and the distributor cap.
3. Removing the Distributor:
* Locate the Hold-Down Bolt: There's typically a single bolt securing the distributor to the engine. Loosen and remove it.
* Mark the Distributor's Position: Before removing the distributor, use a marker to make a mark on the distributor housing and the engine block, aligning them to help you reinstall the distributor correctly. This is crucial for proper timing.
* Remove the Distributor: Carefully rotate the distributor slightly and pull it straight up. Some resistance is normal. Note its position and orientation – this is critical.
* Inspect the Distributor: If you're replacing it due to a suspected modulator problem (which is likely causing your issue), closely examine the internals for wear or damage.
4. Installing the New Distributor:
* Install the New Distributor: Carefully align the distributor according to your markings. Gently push it down until it seats correctly. Tighten the hold-down bolt to the manufacturer's specified torque.
* Reconnect Components: Reconnect the distributor cap, ignition coil wire, and spark plug wires, ensuring they are in the correct order (refer to your markings or photos).
* Reconnect Battery Cable: Reconnect the negative battery cable.
5. Setting the Timing (Crucial):
* Use a Timing Light: Refer to your repair manual for instructions on setting the timing. This step is critical; improper timing can severely damage your engine. If you're unfamiliar with this process, seek professional help.
Important Considerations:
* Distributor Replacement: As mentioned, you likely need to replace the entire distributor, not just a modulator. The modulator is an internal component and isn't typically replaced separately.
* Professional Help: If you're not comfortable working on your engine, take it to a qualified mechanic. Improperly installing a distributor can lead to engine damage.
This is a simplified overview. Always consult a repair manual specific to your 1989 Mustang 302 HO for detailed instructions and diagrams. Safety should always be your top priority when working on your vehicle.
