High Probability Issues:
* Ignition System: Worn spark plugs, bad ignition wires, a failing distributor cap or rotor, or a weak coil can all cause misfires, stalling, and a foul-smelling exhaust (unburnt fuel). The blinking CEL strongly supports this.
* Fuel System: A clogged fuel filter, a failing fuel pump (weak pressure), or problems with the fuel injectors can lead to inconsistent fuel delivery, causing stalling and poor running. A clogged filter would also explain the foul smell.
* Catalytic Converter: If the misfire is severe and prolonged, it can overheat and damage the catalytic converter. This will result in a very strong, foul smell (often described as rotten eggs). A damaged converter itself can also cause back pressure affecting the engine.
Less Likely, but Possible Issues:
* Mass Airflow Sensor (MAF): A faulty MAF sensor provides inaccurate air/fuel readings to the engine computer, leading to poor running and stalling.
* Throttle Position Sensor (TPS): A malfunctioning TPS can cause similar issues as a bad MAF sensor.
* Engine Vacuum Leaks: Leaks in the vacuum system can disrupt the engine's operation, causing idling problems and stalling.
* EGR Valve: A malfunctioning EGR valve can cause rough running and stalling, especially at idle.
Troubleshooting Steps:
1. Read the Diagnostic Trouble Codes (DTCs): The blinking CEL is storing trouble codes. You need a code reader (available at auto parts stores) to read these codes. This will pinpoint the problem area significantly.
2. Check the Spark Plugs, Wires, Distributor Cap, and Rotor: Visually inspect these components for wear, cracks, or damage. Replace if necessary. This is the easiest and cheapest thing to check first given the symptoms.
3. Inspect the Fuel Filter: Replace the fuel filter; it's a relatively inexpensive part and a common cause of fuel delivery problems.
4. Check for Vacuum Leaks: Visually inspect all vacuum lines for cracks or loose connections. Use a vacuum gauge to test the system if you have one.
5. Test the Fuel Pressure: You'll need a fuel pressure gauge to check the fuel pressure. Low fuel pressure indicates a problem with the fuel pump or regulator.
6. Consider the Catalytic Converter: If the exhaust smell is particularly strong (rotten eggs), the catalytic converter might be failing. This is an expensive repair.
Important Note: A blinking Check Engine light indicates a severe problem that could cause further damage if not addressed promptly. Driving with a severely misfiring engine can damage the catalytic converter and potentially cause engine damage. If you're not comfortable performing these repairs yourself, take your Sunbird to a qualified mechanic. They have the tools and experience to properly diagnose and fix the issue.
