1. Get the Diagnostic Trouble Codes (DTCs):
This is crucial. You need to retrieve the codes stored in the car's computer. You can do this in a few ways:
* OBD-I Scanner: A 1994 Intrepid uses an OBD-I system, which is older than OBD-II. You'll need a scanner specifically designed for OBD-I (sometimes called a "code reader" for older vehicles). Auto parts stores often have loaner tools, or you can purchase one relatively inexpensively.
* Paperclip Method (Less Reliable): There's a "paperclip method" for some OBD-I systems, but it's less reliable and can be tricky. Search online for "1994 Dodge Intrepid OBD-I paperclip method" for instructions. This method usually only gives a limited amount of information.
2. Common Causes Based on Symptoms:
Once you have the DTCs, you can research what they mean. However, even without the codes, here are some likely culprits given your description:
* Idle Air Control (IAC) Valve: This valve regulates air flow at idle. A dirty or faulty IAC valve can cause stalling, especially at low RPM. Cleaning it (with carb cleaner) is a relatively simple and inexpensive first step.
* Throttle Position Sensor (TPS): The TPS tells the computer the throttle's position. A faulty TPS can lead to erratic idle and starting problems.
* Crankshaft Position Sensor (CKP): This sensor tells the computer the engine's rotational position. A failing CKP can prevent the engine from starting or cause it to stall.
* Mass Airflow Sensor (MAF): Measures the amount of air entering the engine. A dirty or faulty MAF sensor will cause a lean fuel condition leading to stalling, rough running, and poor starting. Cleaning it (carefully!) is worth trying if you have access to MAF sensor cleaner.
* Fuel Pressure Regulator: Could be leaking causing low fuel pressure at idle.
* Fuel Pump: Although less likely to cause stalling only at idle, a weak fuel pump could contribute to starting and running issues.
* Ignition System: Worn spark plugs, spark plug wires, distributor cap, or rotor can cause misfires leading to stalling and hard starting.
3. Troubleshooting Steps:
* Check all the obvious: Make sure your battery is fully charged and the terminals are clean and tight.
* Check fuel: Ensure you have enough fuel.
* Visual Inspection: Look for any visible damage or loose connections in the engine bay, particularly around the components listed above.
* After getting DTCs: Based on the codes, you can focus your efforts on the specific components indicated.
Important Note: Working on a car's electrical and fuel systems can be dangerous. If you're not comfortable working on cars, it's best to take it to a qualified mechanic. Improper repair could cause further damage.
