* Clogged Fuel Filter: A clogged fuel filter can restrict fuel flow even with a new pump. This is a cheap and easy thing to check and replace.
* Fuel Pressure Regulator: This component regulates fuel pressure in the system. A faulty regulator can cause inconsistent pressure, leading to stalling.
* Crankshaft Position Sensor (CKP Sensor): This sensor tells the engine's computer where the crankshaft is in its rotation cycle. A faulty CKP sensor prevents proper fuel delivery and ignition timing, resulting in stalling.
* Mass Airflow Sensor (MAF Sensor): The MAF sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor provides inaccurate data to the computer, leading to improper fuel mixture and stalling.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle's position. A faulty TPS can cause erratic idling and stalling.
* Ignition System Problems: Issues with the ignition coil, spark plugs, wires, or distributor (if equipped) can prevent the engine from firing properly, leading to stalling.
* Computer Issues (PCM/ECM): While less common, a problem with the Powertrain Control Module (PCM) or Engine Control Module (ECM) can cause stalling. This is usually diagnosed by a mechanic with diagnostic tools.
* Vacuum Leaks: Leaks in the vacuum system can disrupt engine operation and cause stalling.
* Wiring Issues: Damaged or corroded wiring related to any of the above components can interrupt the electrical signals needed for proper operation.
Troubleshooting Steps:
1. Check the Fuel Filter: This is the easiest and cheapest place to start. Replace it with a new one.
2. Check Fuel Pressure: Use a fuel pressure gauge to measure fuel pressure. This will determine if the new pump is delivering adequate pressure.
3. Inspect Wiring and Connections: Look for any damaged, loose, or corroded wires and connectors, particularly those associated with the fuel system, ignition system, and sensors mentioned above.
4. Have it Diagnosed: Take your Neon to a trusted mechanic or auto parts store that offers diagnostic services. They can use a scan tool to read diagnostic trouble codes (DTCs) which might pinpoint the exact problem.
Don't just continue to randomly replace parts. Systematic troubleshooting is key to finding the root cause of the stalling problem efficiently and cost-effectively. Start with the simpler checks (fuel filter, visual inspection of wiring) before moving to more complex components.
