* Ignition System Problems: This is the most probable cause. The flashing light indicates a severe misfire, and the '97 Mark VIII uses a complex ignition system. Look at:
* Spark Plugs and Wires: Worn, damaged, or improperly gapped spark plugs are common causes of misfires. Worn spark plug wires can also lead to poor spark delivery.
* Ignition Coils: These are responsible for boosting the voltage to the spark plugs. A failing coil will cause a misfire in the cylinder(s) it controls. The Mark VIII uses individual coils for each cylinder, making diagnosis easier (a cylinder-specific misfire points to its corresponding coil).
* Ignition Control Module (ICM): This module controls the ignition timing and spark delivery. A faulty ICM can cause multiple misfires.
* Crankshaft Position Sensor (CKP): This sensor tells the computer the engine's rotational position, crucial for proper ignition timing. A bad CKP sensor leads to erratic engine operation and misfires.
* Cam Position Sensor (CMP): Similar to the CKP, but it monitors the camshaft position. A faulty CMP can affect valve timing and ignition timing, leading to misfires.
* Fuel System Issues: Though less likely given the flashing light (misfire is more prominent), problems here could exacerbate the situation:
* Fuel Injectors: A clogged or faulty injector can prevent proper fuel delivery to a cylinder, leading to a misfire.
* Fuel Pump: A weak or failing fuel pump might not supply enough fuel at the required pressure. This is less likely to cause a *flashing* check engine light, though.
* Fuel Filter: A clogged fuel filter restricts fuel flow.
* Other Potential Problems (Less Likely):
* Mass Airflow Sensor (MAF): A faulty MAF sensor provides inaccurate air readings to the engine computer, leading to a poor air-fuel mixture and potentially misfires.
* Engine Vacuum Leaks: Significant vacuum leaks can disrupt engine operation and cause misfires.
What to Do:
1. Don't drive it extensively: Continued driving with a flashing check engine light and rough running can cause significant engine damage.
2. Get a Diagnostic Scan: The most important step is to get the car's trouble codes read using an OBD-II scanner. This will pinpoint the specific problem areas reported by the car's computer. Auto parts stores often offer free code reading services.
3. Inspect Visually: Once you have the codes, start visually inspecting the easily accessible components like spark plugs and wires. Look for cracks, damage, or corrosion.
4. Professional Help: If you're not comfortable working on your car yourself, take it to a qualified mechanic. The nature of the problem and the flashing light suggest a potential for serious engine damage if not addressed promptly.
The flashing check engine light signifies a critical issue that demands immediate attention. Delaying repairs could lead to costly engine damage. Getting a diagnostic scan is the first, most crucial step towards resolving the problem.
