Fuel System:
* Clogged Fuel Filter: A clogged filter restricts fuel flow, leading to starting problems and stalling, especially when the engine is idling and demanding less fuel. This is a relatively cheap and easy fix.
* Fuel Pump: A weak or failing fuel pump might not supply enough pressure, causing starting difficulties and stalling, particularly when the engine is under load (even slight load at idle).
* Fuel Injectors: Clogged or malfunctioning fuel injectors can lead to inconsistent fuel delivery, resulting in rough idling and stalling. Cleaning or replacing injectors might be necessary.
* Vacuum Leaks: Leaks in the vacuum lines can disrupt fuel delivery and air/fuel mixture, leading to poor idle and stalling. Inspect all vacuum lines for cracks or loose connections.
Ignition System:
* Distributor Cap and Rotor: These parts wear out over time and can cause misfires, leading to rough running and stalling. Inspect for cracks, corrosion, or wear.
* Ignition Coil: A failing ignition coil can't provide sufficient spark to ignite the fuel-air mixture, resulting in starting problems and stalling.
* Spark Plugs and Wires: Worn, fouled, or damaged spark plugs and wires can cause misfires and poor performance. Replace them if they're old or show signs of wear.
* Crankshaft Position Sensor (CKP Sensor): This sensor tells the computer the engine's rotational speed. A faulty sensor can prevent the engine from starting or cause it to stall.
Other Potential Issues:
* Idle Air Control (IAC) Valve: This valve regulates air flow at idle. A dirty or malfunctioning IAC valve can cause rough idling and stalling. Cleaning it is often sufficient.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty TPS can lead to poor idle and stalling.
* Mass Airflow Sensor (MAF Sensor): This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can cause poor running and stalling.
* Battery and Alternator: A weak battery or malfunctioning alternator can prevent starting. Test the battery and alternator's charging system.
Troubleshooting Steps:
1. Check the obvious: Start with the easiest and cheapest fixes: Check the fuel filter, inspect the spark plugs and wires, and look for any visible vacuum leaks.
2. Listen carefully: Does the engine crank but not start? Does it start but immediately stall? Does it run rough before stalling? These clues can help narrow down the problem.
3. Use a diagnostic tool: A OBD-II scanner (if your 1994 Aspire has this capability; check your owner's manual) can read trouble codes that pinpoint the problem area. This is a valuable tool for modern diagnostics.
4. Professional help: If you're not comfortable working on your car yourself, take it to a mechanic. They have the tools and expertise to diagnose and fix the problem efficiently.
Remember safety first! Work in a well-ventilated area, disconnect the battery negative terminal before working on electrical components, and use appropriate safety gear. Good luck!
