* Crankshaft Position Sensor (CKP): This sensor is crucial for determining engine timing. Cold temperatures can affect its performance, leading to misfires and difficulty starting. A failing CKP often manifests as a problem starting when cold, but once the engine warms up, it functions adequately until it cools down again.
* Throttle Position Sensor (TPS): A malfunctioning TPS can provide inaccurate information to the engine control module (ECM) about throttle position. This can lead to a lean fuel mixture when cold, making starting difficult. Similar to the CKP, the issue might resolve itself once the engine and sensor warm up.
* Mass Airflow Sensor (MAF): The MAF sensor measures the amount of air entering the engine. A dirty or malfunctioning MAF can cause an inaccurate fuel mixture, especially noticeable during cold starts when the engine needs a richer mixture.
* Fuel Injector Issues: While you've replaced the fuel filter, the injectors themselves could be contributing. Cold fuel can cause issues with injector spray pattern or flow, especially if they are worn or dirty. Injectors may need cleaning or replacement.
* Ignition Coil: Although you replaced the cap and rotor, the ignition coil itself could be weak. Cold temperatures can exacerbate weak coil performance.
* Battery/Alternator: A weak battery or alternator might not provide sufficient power for the starter motor when the engine is cold, leading to slow cranking or failure to start. Cold weather significantly reduces battery power.
Troubleshooting Steps:
1. Check for diagnostic trouble codes (DTCs): Use a scan tool (OBD-I for a '92 Silverado) to see if the ECM has stored any codes. These codes can point directly to the problem.
2. Test the battery and charging system: Make sure the battery is fully charged and the alternator is charging properly.
3. Inspect the CKP and TPS: Check their connections for corrosion and visually inspect them for damage. If possible, test their resistance and voltage output using a multimeter (consult a repair manual for specific testing procedures).
4. Clean the MAF sensor: Use MAF sensor cleaner specifically designed for this purpose. Do not touch the sensor element.
5. Check fuel pressure: This requires a fuel pressure gauge to measure the pressure at the fuel rail. Low pressure could indicate a problem with the fuel pump or regulator.
6. Consider professional diagnosis: If you're not comfortable working on your vehicle's electrical system, it's best to take it to a qualified mechanic. They have the tools and expertise to diagnose the issue accurately.
Remember that the symptoms are pointing toward a temperature-sensitive component, making the CKP, TPS, MAF, or fuel injectors the most likely culprits. A proper diagnostic check is key to resolving this.
