1. Identify the Firing Order: The firing order for the 1991 Ford Taurus SHO's Yamaha V6 is 1-6-5-4-3-2. This is crucial. Write it down clearly.
2. Gather Your Supplies:
* New spark plug wires (ensure they are the correct length and type for your SHO)
* Socket wrench and extension for spark plugs (if you're also changing plugs, do it now!)
* Pliers (possibly needle-nose) for removing old wires
* Wire routing diagram (if you have one from a repair manual; highly recommended)
* A marker (to label wires if necessary)
* Shop rag or towel
3. Disconnect the Battery: Always disconnect the negative (-) battery terminal before starting any electrical work.
4. Remove Old Wires: Carefully pull off each spark plug wire one by one, paying attention to where each one connects. Sometimes they can be stubborn; gently wiggle and pull. Take pictures or make notes if necessary, but relying on memory is risky here.
5. Install New Wires: This is where the firing order is paramount. Refer to your firing order (1-6-5-4-3-2). Starting with cylinder #1, install the new wire in the correct spark plug boot, ensuring a secure connection.
* Finding Cylinder #1: The easiest way is usually to refer to a repair manual or online diagram showing the engine layout and cylinder numbering. The location may vary depending on whether the engine is viewed from the front or the side.
* Following the Firing Order: Once you've connected #1, use your firing order to find the correct spark plug for cylinder #6, then #5, and so on. Follow the wire's path carefully; don't force it.
* Secure Connections: Make sure each wire is firmly seated on both the distributor cap (if applicable) and the spark plug. A loose connection will cause misfires.
6. Reconnect the Battery: Once all wires are in place, carefully reconnect the negative (-) battery terminal.
7. Start the Engine: Start the engine and listen for any misfires. Rough running or hesitation indicates a wiring issue. Double-check the connections. If it runs poorly, you'll likely need to recheck your work.
Important Considerations:
* Repair Manual: A factory service manual is *invaluable*. It will have diagrams showing the firing order, wire routing, and cylinder location. Investing in one is a good idea for any major repairs.
* Routing: Route the wires as close as possible to the original path to avoid interference and damage.
* Spark Plugs: While not directly part of wire replacement, it's highly recommended to replace spark plugs at the same time. Old plugs can cause misfires regardless of new wires.
* Distributor Cap and Rotor (if applicable): If your SHO has a distributor, examine the cap and rotor for wear or damage. Replace them if necessary.
If you are uncomfortable performing this task yourself, take your Taurus SHO to a qualified mechanic. Incorrectly installed wires can damage your engine. It's better to pay a professional than risk significant repair costs later.
