* Spark Plugs & Ignition System: Worn, fouled, or incorrectly gapped spark plugs are a common cause of rough running, especially under acceleration. The ignition leads (HT leads) could also be cracked or worn, leading to misfires. The ignition coil(s) themselves could be failing.
* Fuel System: Problems in the fuel delivery system can also cause rough running. This could include:
* Fuel filter: A clogged fuel filter restricts fuel flow, leading to poor performance and rough running.
* Fuel pump: A failing fuel pump might not deliver enough fuel under increased demand (acceleration).
* Fuel injectors: Clogged or faulty injectors can cause inconsistent fuel delivery to the cylinders.
* Mass Airflow Sensor (MAF) Sensor: This sensor measures the amount of air entering the engine. A faulty MAF sensor provides incorrect information to the engine computer, leading to a poor air/fuel mixture and rough running.
* Throttle Position Sensor (TPS): This sensor tells the engine control unit (ECU) the throttle position. A faulty TPS can cause incorrect fuel delivery and timing, resulting in rough running.
* Oxygen Sensor(s): These sensors measure the oxygen levels in the exhaust. Faulty oxygen sensors can lead to a rich or lean fuel mixture, affecting engine performance.
* Engine Management System (ECU): Although less common, a problem with the ECU itself can cause various engine issues, including rough running.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the engine's performance and lead to uneven running.
* Air intake system: Restrictions in the air intake system (e.g., dirty air filter) can reduce the amount of air available, resulting in poor engine performance.
Troubleshooting Steps (in order of easiest to most difficult):
1. Check the basics: Start with the easiest checks: Inspect the air filter, check the condition of the spark plugs and leads, and visually inspect the fuel filter (if accessible).
2. Get diagnostic codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the ECU. These codes can point towards the specific component causing the problem.
3. Professional diagnosis: If you can't identify the problem using the above steps, it's best to take your vehicle to a qualified mechanic specializing in Fords or Australian-made vehicles. They have the tools and experience to properly diagnose and fix the issue.
Remember safety first! If the engine is running very roughly, it's best not to drive it until the problem is diagnosed and fixed.
